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@inproceedings{bib_A_re_2022, AUTHOR = {Mangeshkumar R. Shendkar, Denise-Penelope N. Kontoni, Pradeep Kumar Ramancharla, Ahmed Abdelraheem Farghaly, Sasankasekhar Mandal, Pabitra Ranjan Maiti}, TITLE = {A refined procedure for seismic evaluation and retrofitting of reinforced concrete buildings}, BOOKTITLE = {Current Science}. YEAR = {2022}}

In the present study, a refined procedure for the seismic evaluation and retrofitting of reinforced concrete (RC) buildings based on the ‘quadrants assessment method’ and ‘material strain limit approach’ is proposed and numerically analysed. The quadrants assessment method involves the performance point, design base shear and threshold damage limit state. Herein, four existing RC buildings (models 1–4) are considered from the Koyna– Warna region, Maharashtra (zone-IV, India). These four buildings were studied using nonlinear static adaptive pushover analysis employing the SeismoStruct software. Based on the quadrants assessment method, the three-storey RC building (model-1) was retrofitted with RC jacketing, while the other three RC buildings did not need to be retrofitted. Also, significant seismic design parameters like ductility, over strength factor, response reduction factor, etc. were evaluated before and after retrofitting. The results depict that the combination of the ‘quadrants assessment method’ and ‘material strain limit approach’ is a rapid, reliable and refined procedure for seismic evaluation and retrofitting of RC buildings.

@inproceedings{bib_Simu_2022, AUTHOR = {Chenna Rajaram, Pradeep Kumar Ramancharla}, TITLE = {Simulation of Near-Fault Seismic Ground Motions of 03 November, 2002 Denali Earthquake Using Modified Semi-Empirical Approach}, BOOKTITLE = {Civil Engineering Infrastructures Journal}. YEAR = {2022}}

An effective earthquake (Mw 7.9) struck Alaska on 3 November, 2002. It ruptured 340 km along three faults namely, the Susitna Glacier, Denali and Totschunda faults in central Alaska. The earthquake was recorded at 23 stations in Alaska and the Peak Ground Acceleration (PGA) of 0.32g was recorded at station PS10, which was located 3 km from the fault rupture. In this study, strike-slip Denali fault has been considered for studying the characteristics of ground motions through modified semiempirical approach. The ground motion records of the 2002 Denali earthquake are generated through MATLAB code. The results revealed that modified semi-empirical approach is fairly good in agreement with observed ground motion records at all stations. A perfect match is observed between Fourier amplitude spectra of simulated and observed ground motions at PS09 and CARLO stations. A good match is observed between elastic response spectra of observed and simulated ground motions. Keywords: Denali Earthquake, Fourier Amplitude Spectrum, Ground Motion Prediction Equation, Synthetic Accelerogram.

@inproceedings{bib_Seis_2022, AUTHOR = {Rajaram Chenna, Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {Seismic hazard and vulnerability scenario of Kathmandu, Nepal, and adjacent region}, BOOKTITLE = {innovative Infrastructure Solutions}. YEAR = {2022}}

The main objective of the current study is to estimate the seismic vulnerability of buildings in Kathmandu valley through fragility curves. Since the ground motion records are limited for the April 25, 2015, Nepal earthquake, a MATLAB code is written to generate the artificial ground motion records considering each mandal as a site location. Earlier written MATLAB code has been modified with a correction function to obtain synthetic accelerograms at each station. A spatial seismic hazard distribution is plotted through Geographical Information System (GIS) software. Seismic fragility curves are drawn to estimate the damage of buildings.

@inproceedings{bib_Trem_2022, AUTHOR = {Velani Pulkit Dilip, Neelima Patnala, Prakke Bharat, SALAKA LAKSHMI NARASIMHA SASTRY, Pradeep Kumar Ramancharla}, TITLE = {Tremors and built environment of Hyderabad,Telangana, India: safety of buildings using recorded ground motions}, BOOKTITLE = {Current Science}. YEAR = {2022}}

Although the city of Hyderabad in Telangana, India lies in seismic zone II, low to medium intensity tremors that pose a serious concern towards safety of the built envi- ronment are not uncommon. One such series of tremors occurred during 13–20 October 2020, in the financial district of Hyderabad and created a panic situation due to perceivable shaking and jolts with loud sounds associ- ated with hydro-seismicity. To understand the safety of the city’s built environment, a study was conducted on low, medium and tall buildings using ground motions recorded at the International Institute of Information Technology (IIIT), Hyderabad, which is 2.3 km from the epicentre. The amplification of ground motion on the second floor of the Nilgiri Building in IIIT, Hyderabad was 1.2–2.3. The vibrations recorded on the ground floor of the Nilgiri Building were used to develop a site-speci- fic response spectrum. This was further used to obtain the peak responses of the considered buildings through response spectrum analysis. The present study suggests that the low-rise buildings, mid-rise buildings and non- structural elements in high-rise buildings are under threat in the case of high-intensity earthquakes.

@inproceedings{bib_Trem_2022, AUTHOR = {Velani Pulkit Dilip, Neelima Patnala, Bharat Prakke, S. L. N. Shastry, Pradeep Kumar Ramancharla}, TITLE = {Tremors and built environment of Hyderabad, Telangana, India: safety of buildings using recorded ground motions}, BOOKTITLE = {Current Science}. YEAR = {2022}}

Although the city of Hyderabad in Telangana, India lies in seismic zone II, low to medium intensity tremors that pose a serious concern towards safety of the built environment are not uncommon. One such series of tremors occurred during 13–20 October 2020, in the financial district of Hyderabad and created a panic situation due to perceivable shaking and jolts with loud sounds associated with hydro-seismicity. To understand the safety of the city’s built environment, a study was conducted on low, medium and tall buildings using ground motions recorded at the International Institute of Information Technology (IIIT), Hyderabad, which is 2.3 km from the epicentre. The amplification of ground motion on the second floor of the Nilgiri Building in IIIT, Hyderabad was 1.2–2.3. The vibrations recorded on the ground floor of the Nilgiri Building were used to develop a site-specific response spectrum. This was further used to obtain the peak responses of the considered buildings through response spectrum analysis. The present study suggests that the low-rise buildings, mid-rise buildings and nonstructural elements in high-rise buildings are under threat in the case of high-intensity earthquakes.

@inproceedings{bib_UAV-_2022, AUTHOR = {Kushagra Srivastava, Kushagra Srivastava, Aditya Kumar Jha, Mohhit Kumar Jha, Jaskirat Singh, Santosh Ravi Kiran, Pradeep Kumar Ramancharla, Harikumar K, K Madhava Krishna}, TITLE = {UAV-based Visual Remote Sensing for Automated Building Inspection}, BOOKTITLE = {European Conference on Computer Vision Workshops}. YEAR = {2022}}

Unmanned Aerial Vehicle (UAV) based remote sensing system incorporated with computer vision has demonstrated potential for assisting building construction and in disaster management like damage assessment during earthquakes. The vulnerability of a building to earthquake can be assessed through inspection that takes into account the expected damage progression of the associated component and the component’s contribution to structural system performance. Most of these inspections are done manually, leading to high utilization of manpower, time, and cost. This paper proposes a methodology to automate these inspections through UAV-based image data collection and a software library for post-processing that helps in estimating the seismic structural parameters. The key parameters considered here are the distances between adjacent buildings, building plan-shape, building plan area, objects on the rooftop and rooftop layout. The accuracy of the proposed methodology in estimating the above-mentioned parameters is verified through field measurements taken using a distance measuring sensor and also from the data obtained through Google Earth. Additional details and code can be accessed from h

@inproceedings{bib_Use__2022, AUTHOR = {Swapnil Nayan, Pradeep Kumar Ramancharla}, TITLE = {Use of machine learning algorithms for damage estimation of reinforced concrete buildings}, BOOKTITLE = {Current Science}. YEAR = {2022}}

One thousand two hundred and ninety-six different building models were designed and analysed using SAP2000 (ref. 13). Each building model belongs to one of the types mentioned in Table 1 and have been obtained using every permutation of the parameters listed in Table 2. Timehistory (TH) analysis was performed on these models to obtain MISDR, which was then used for training and testing.

@inproceedings{bib_A_Ne_2021, AUTHOR = {P.Sushma, Pradeep Kumar Ramancharla}, TITLE = {A Need to Include Provisions of SSI in IS:1893 : Case Study on Soil-Structure-Interaction of Pile Supported Frame Structure}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2021}}

Experiences from past earthquake disasters clearly shows that the ground motion was responsible for majority of property and life loss. Among the collapsed structures during the 1964 Niigata earthquake, the 1995 Kobe earthquake, the 1999 Kocaeli (Izmit) earthquake, the 2001 Bhuj earthquake and the 2004 Sumatra earthquake, excessive damage had occurred to pile supported bridges, towers, chimneys, high rise structures, etc. In view of this there is a need to study the complex behaviour of soil-pile-structure interaction problems. However, clause 6.1.5 IS 1893-2016, says that soil-structure-interaction (SSI) is not needed for structures founded on rock at shallow depth, but not enough details are given for SSI.

@inproceedings{bib_SEIS_2021, AUTHOR = {Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {SEISMIC SAFETY OF 4 STOREY REINFORCED CONCRETE OPEN GROUND STOREY STRUCTURE}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2021}}

Earthquake safety of buildings is one of the primary concerns of structural engineers throughout the world. The performance of buildings during past earthquakes has brought out the lacunas in design, analysis and execution of these structures. The constant endeavour for uniqueness has led to the distribution of irregularities along the plan and height of buildings. One of such attempts is the development of Open Ground Storey (OGS) buildings. It is the dominant parameter having vertical irregularity, if not rectified, may often lead to the collapse of structure. Reinforced concrete building with OGS; absence of infill wall in a ground storey, is prevailing construction practice in most places in India. It causes a sudden decrease in lateral stiffness (K) and strength (V), from adjacent upper to ground storey, results in accumulation of stresses due to large lateral displacement in ground storey columns to cause soft storey effect. The problem can be solved by increasing K and V of the ground storey relative to the adjacent upper storey. Seismic codes specify the design process for buildings with OGS by relative K and V of ground and adjacent upper storey. Quantifying design criteria for such structural configurations based on Design Amplification Factor (DAF) for ground storey columns is preferable. K and V of storey depends on masonry strength, central opening (OP) in infills and interaction between wall infill and frame. In the current study, DAF is proposed to overcome OGS effect considering the above parameters. Additional parameters like Stiffness factor (KF) and strength factor (VF), ratios of elastic lateral stiffness (KE) and maximum

@inproceedings{bib_Mome_2021, AUTHOR = {Niharika, Pradeep Kumar Ramancharla}, TITLE = {Moment of Inertia as per IS Code Provisions: A Review}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2021}}

The advent of the cracked moment of inertia (MoI) in Indian code provisions has sparked many discussions and confusions regarding what MoI is to be used in the design of structures in service load case and ultimate load case. The intent of this study is to understand the uncracked and cracked moment of inertia, what code provisions recommend, their applicability and the possible reasoning behind the recommendations. Solved examples are presented along with this review study to clear the usage of cracked MoI and u n d e r s t a n d t h e s i g n i  c a n c e o f s u c h recommendations.

@inproceedings{bib_Nume_2021, AUTHOR = {Chenna Rajaram, Pradeep Kumar Ramancharla}, TITLE = {Numerical Modeling of Near Fault Seismic Ground Motion for Denali Fault}, BOOKTITLE = {International Journal of Geotechnical Earthquake Engineering}. YEAR = {2021}}

An effective earthquake (Mw 7.9) struck Alaska on 3 November 2002. This earthquake ruptured 340 km along Susitna Glacier, Denali, and Totschunda faults in Central Alaska. The peak ground acceleration (PGA) was recorded about 0.32 g at station PS10, which was located 3 km from the fault rupture. The PGA would have recorded a high value if more instruments had been installed in the region. A numerical study has been conducted to find out the possible ground motion record that could occur at maximum horizontal slip during the Denali earthquake. The current study overcomes the limitation of number of elementsto model the Denali fault. These numerical results are compared with observed ground motions. It is observed that the ground motions obtained through numerical analysis are in good agreement with observed ground motions. From numerical results, it is observed that the possible expected PGA is 0.62 g at maximum horizontal slip of Denali fault.

@inproceedings{bib_Prel_2021, AUTHOR = {Chenna Rajaram, Pradeep Kumar Ramancharla}, TITLE = {Preliminary Estimation of Ground Motion of Pakistan Earthquake Using Modified Semi-Empirical Approach}, BOOKTITLE = {Journal of Seismology and Earthquake Engineering}. YEAR = {2021}}

Hazard plays a vital role in assessing the risk of any area. For earthquake hazard estimation, it is essential to obtain ground motion records from various seismic stations. However, it is not always easy to get ground motion data. The present study is an attempt to generate ground motions of the recent September 24, 2013, Pakistan earthquake using modified semi-empirical approach, which is based on w2 model. The first part of the method considers a time series having the basic spectral shape of acceleration. The deterministic model of rupture source has been used in the second part ofthe method to simulate the envelope of accelerogram. For the study, a MATLABcode is written to generate synthetic accelerograms atstations Awaran, Panjgur, Tagas, Korak, and Gajar. The results are compared with Ground Motion Prediction Equation (GMPE) proposed byRamkrishnan et al., in 2019 [1]. The PGAvalues obtained from modified semi-empirical method gives satisfactorily good results in comparison with the PGAvaluesfromGMPE. However, slight variation is observed between synthetic accelerogram PGAvalues and GMPE values at Gajar, Korak, Tagas, Panjgur stations.

@inproceedings{bib_A_co_2021, AUTHOR = {Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {A comparative study of different rapid visual survey methods used for seismic assessment of existing buildings}, BOOKTITLE = {Structures}. YEAR = {2021}}

Determination of seismic safety of existing buildings is a time consuming and challenging process. Instead, rapid survey methods were developed which identify deficient structures from a large building stock in a city or town. This paper presents a comparison and critical review of existing rapid visual survey methods used for seismic assessment of existing reinforced concrete buildings. The study focuses on rapid visual survey methods developed for the safety assessment of reinforced concrete buildings in the Indian subcontinent and a widely used method in the United States. Comparison is carried out in various ways. Initially, a direct comparison is made based on vulnerable parameters and damage grades proposed by each method. Later, a scoring system is developed to highlight the differences and rank the selected methods. This system considers the general description, physical parameters, and damage description. Finally, as a case study, a rapid visual survey was conducted on 100 reinforced concrete buildings in each of the three cities (i.e., Pithoragarh, Gangtok, and Agartala) in India. These cities have different seismic, geological, and topographical conditions. The results show that all five methods give different outputs for the same sample surveyed buildings in each city. It was observed that there are many uncommon vulnerability parameters amongst each selected method. The results show a considerable variation in the weights assigned to each vulnerable parameter in all five methods.

@inproceedings{bib_Prot_2021, AUTHOR = {Pradeep Kumar Ramancharla, C. V. R. Murty}, TITLE = {Protecting the Built Environment from Earthquakes}, BOOKTITLE = {The Journal of Governance}. YEAR = {2021}}

Earthquakes cause disasters only when the built environment fails to resist the earthquake shaking experienced in the affected area, thereby causing losses of life and property. Ensuring structural safety of the built environment alone will result in earthquake safety of India. India needs suffcient number of competent structural, geotechnical engineers and architects to design and construct its new earthquake resistant buildings and facilities and to retroft its existing ones. This paper urges quantum changes in the educational, social, technical, fnancial, techno-legal, industrial and administrative governance systems of the country, and re-iterates the stand of the nation of zero tolerance to avoidable deaths due to earthquakes.

@inproceedings{bib_Seis_2021, AUTHOR = {Mangeshkumar R. Shendkar , Pradeep Kumar Ramancharla, Sasankasekhar Mandal , Pabitra Ranjan Maiti, Denise‑Penelope N. Kontoni}, TITLE = {Seismic risk assessment of reinforced concrete buildings in Koyna‑Warna region through EDRI method}, BOOKTITLE = {innovative Infrastructure Solutions}. YEAR = {2021}}

The Koyna-Warna region of Maharashtra, India, is one of the most signifcant worldwide examples for reservoir-induced seismicity. The area is highly vulnerable to earthquakes, and it has experienced over 1 lakh number of shocks since 1963. The largest known earthquake of magnitude 6.5 (Richter scale) occurred on 10th December 1967. Many low and moderate earthquake events have occurred over the past 50 years. A structured survey using rapid visual screening was carried out for existing RC buildings. The seismic risk index depends on three parameters, viz. hazard, exposure, and vulnerability. Many existing RC buildings in the Koyna-Warna region are designed to resist the gravity loads only without any seismic resistant provisions. Hence, there is a need to study the risk index of these RC buildings to assess future serious risks. In this study, the rapid visual survey of 120 existing RC buildings has been done through a modifed EDRI method (Earthquake Disaster Risk Index) to evaluate the seismic risk index of the Koyna-Warna region (Zone-IV as per IS: 1893–2016). The results depict that the risk index of RC buildings in the Koyna-Warna region is in severe damage condition and hence there is a need to take an initiatives for earthquake preparedness plan, with emphasis on retroftting measures, to reduce the loss of human life and damage to physical infrastructure in future seismic events.

@inproceedings{bib_A_co_2021, AUTHOR = {Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {A comparative study of different rapid visual survey methods used for seismic assessment of existing buildings}, BOOKTITLE = {Structures}. YEAR = {2021}}

Determination of seismic safety of existing buildings is a time consuming and challenging process. Instead, rapid survey methods were developed which identify deficient structures from a large building stock in a city or town. This paper presents a comparison and critical review of existing rapid visual survey methods used for seismic assessment of existing reinforced concrete buildings. The study focuses on rapid visual survey methods developed for the safety assessment of reinforced concrete buildings in the Indian subcontinent and a widely used method in the United States. Comparison is carried out in various ways. Initially, a direct comparison is made based on vulnerable parameters and damage grades proposed by each method. Later, a scoring system is developed to highlight the differences and rank the selected methods. This system considers the general description, physical parameters, and damage …

@inproceedings{bib_Veri_2020, AUTHOR = {Pammi Raghu Nandan Vyas, Pradeep Kumar Ramancharla}, TITLE = {Verification of the sufficiency of adjustment of Mass for compensating accidental eccentricities IS 1893:2016 Clause7.8.2}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2020}}

Twisting of a building about vertical axis increases the shear force demand on lateral force resisting elements and it is not desirable as increased shear force results in brittle failure. Generally, twisting is induced in a building due to eccentricity between centre of Mass (CM) and centre of Stiffness (CS) at diaghragm level. Eccentricity can be induced in a structure due to mass, strenght and stiffness arising out of various construction and design limitations. Code insists to apply design forces calculated according to equivalent static method or response spectrum method at displaced center of Mass (CM) so as to cause design eccentricity between CM and CS. The displaced center of mass resulting from design eccentricity consists of two terms static eccentricity and accidental eccentricity. Also, earthquake ground motion has the ability to induce torsion in a structure. Hence in order to account for all the eccentricities, code suggests 5% accidental eccentricity to be included in design eccentricity. In current work, an adjustment of mass eccentricity is verified. For this purpose, three one storey models are created with 5 % unidirectional mass eccentricity (CM), 5% unidirectional stiffness eccentricity (CS) and 5% unidirectional Mass-Stiffness eccentricity (CM-CS). Linear Increment Dynamic Analysis is performed by considering chamoli earthquake and edge displacements are obtained. Later, twist is calculated based on edge displacements. It is concluded that the same amount of mass and stiffness eccentricity (i.,e 5%) , the twist incurred in stiffness eccentric model is signifcantly higher whereas no twist about vertical axis is noticed in mass eccentric model unless mass eccentricity has significant impact on torsional response, the torsional response of combined CM-CS eccentric model is approximately equal to CS eccentric model. The results conclude that universal adjustment of center of mass will not provide the assumed conservativeness of safety against torsion. Apart from this, few countries guidelines like New Zealand [NZS, 2004] has revised accidental eccentricity from 5% to 10%. Hence, design eccentricity needs revision considering the statistical evaluation of various paramters inducing accidental eccentricities , without adjusting mass centre for every eccentricity.

@inproceedings{bib_COMP_2020, AUTHOR = {Pammi Raghu Nandan Vyas, Pradeep Kumar Ramancharla}, TITLE = {COMPARISION OF DIRECT DISPLACEMENT SEISMIC DESIGN WITH FORCE BASED DESIGN USING INDIAN STANDARDS – A CASE STUDY}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Development of Force-based seismic design is historical, and every earthquake has thrown new challenges for already existing assumptions and principles, which helped in the evolution of force-based design. Although many of the assumptions were answered but some remained unaltered and unanswered. Hence, this paved way for developing new theories and philosophies and one such theory is Direct Displacement-Based seismic Design (DDBD). Indian Standard codes, IS 1893 and IS 13920, underwent a major revision in the year 2016, considering the latest developments in Force based design principles. Current work is an attempt to understand the performance comparison between latest IS 1893 & IS 13920 with DDBD method. Initially, three buildings i.e., 3, 6 and 9 storey buildings were designed using DDBD at inter-storey drift of 4% with a performance objective to achieve “No collapse”. The spectrum developed using IS code equations does not represent ideal displacement spectrum shape and hence PGA, T and CA dependent equations are used for DDBD methodology of design. PGA of 0.36g is used in the current study which represents the highest seismic zone in India. Later these buildings were subjected to lateral displacement using displacement-based pushover analysis method. The inelastic strength along with drifts achieved by DDBD are compared with the IS code compliant buildings. From the comparison, it was observed that inelastic strength achieved by 6,9 storey buildings designed according to FBD are greater than the buildings designed according to DDBD at “No Collapse”. For 3 storey structure, the strength achieved by FBD is less than DDBD. If zone is reduced from Zone V to IV or PGA is increased from 0.36g, then inelastic strength achieved by DDBD with performance objective “No Collapse” would be more than FBD requiring revision of response reduction values for different categories of buildings or PGA values in respective seismic zones. The inelastic drifts achieved by both the methods are comparable only for 3 storey structure.

@inproceedings{bib_ESTI_2020, AUTHOR = {Chenna Rajaram, Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {ESTIMATION OF SEISMIC HAZARD FOR KATHMANDU, NEPAL AND ADJACENT REGIONS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

An earthquake Mw7.8 occurred on 25 April 2015 in a seismically dominant area of Nepal. No major earthquakes (>Mw7.0) were recorded in the past two decades, though Nepal is one of the active seismic regions in the world. The combined effect of the main event and the aftershocks, which are temporally distributed over 40 days, has led to a huge devastation, killing thousands of people in the epi-central area. A complete seismic catalog and influencing parameters such as type of fault, epi-central/hypo-central distance, type of soil are required for a region to assess seismic hazard scenario. The seismic hazard can be represented in terms of Peak Ground Acceleration (PGA), which is the most widely used parameter in strong motion studies. The main objective of this paper is to understand the characteristics of ground motion of the 2015 Nepal earthquake. Since the available ground motion records are limited, an attempt has been made to generate ground motion records using a modified semi-empirical approach. Contour maps of PGA and intensity have also been generated. It is observed that around 22% of buildings experienced an intensity of VI on MMI scale at Bageswari mandal. A few buildings have experienced an intensity of VII in Thankot, Seuchatar, Satikhel, Mahadevathan, Indrayani, Chhaimale, and Balambu.

@inproceedings{bib_A_Ca_2020, AUTHOR = {DASARI HIMA CHANDAN, Pradeep Kumar Ramancharla}, TITLE = {A Case Study on Modal dynamic Identification of building from Mild earthquake responses}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

In last two decades, operational modal analysis is widely used for modal identification of structures which uses ambient responses of structure for determining the modal parameters and Frequency Domain Decomposition is one of the most popular method, but seismic excitations and high damping values of structures do not satisfy the assumptions of this classical method. The dynamic modal parameters derived from earthquake responses are more reliable than those from small amplitude responses since dynamic properties of civil structures are dependent on amplitude. In recent years, a new algorithm known as refined Frequency Domain Decomposition (rFDD) is developed which uses structural response to strong ground motions that can be short in duration and is applicable for structures with light to heavy damping. The refined Frequency Domain Decomposition (rFDD) algorithm was initially developed using synthetic seismic response signals as input and later real strong motion response records were used to demonstrate the effectiveness of this algorithm for modal dynamic identification of structures under real earthquake excitations. This method is well developed to counter the problems that normally arise in modal identification and in cases of heavy damping and non-stationarity of the signal, making it lengthy and tedious to process. In this paper the main feature of this method which is Integrated Power Spectral Density matrix computation is taken and applied on mild earthquakes responses of structure. The modal parameters identified are then compared with target values obtained from classical FDD method using ambient responses and interpreted, presenting a case for usage of rFDD in simplified manner in modal dynamic identification of structures. Keywords: Operational Modal analysis, mild earthquake response, refined Frequency Domain Decomposition

@inproceedings{bib_QUAN_2020, AUTHOR = {Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {QUANTIFICATION OF DAMAGE USING HINGE PATTERN IN RC MOMENT RESISTING FRAME BUILDINGS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Damage index models are used for quantification of damage in any numerical model of a building. While using any particular damage model there is high possibility that it might give similar result for two identical structures, each having different attributes. So, though currently available damage index models precisely quantify damage in the structure but fails to identify the reason or attributes/irregularities present in it. Therefore, for quantitative assessment, a unique aspect should be used which will depend on structural as well as architectural features. This paper presents new method for quantification of damage for reinforced concrete (RC) moment resisting framed (MRF) structures using the pattern of hinge formation in structure when it is subjected to a monotonic loading. A two-dimensional RC MRF structures with different building irregularities were modeled. As a primary step to estimate the damage from the pattern of hinge formation, it is necessary to understand and study the relation between damage and hinge pattern. For this purpose, energy-based damage index model is used. The relation between damage index and pattern of hinge formation is studied with the help of regression analysis. A multiple regression analysis is performed taking damage index as dependent variable and the number of hinges formed in each damage state as independent variables. The paper also discusses two different approaches for regression analysis determining the corresponding coefficients. The regression analysis resulted in an equation which can approximately quantify the damage in the structure using total number of hinges formed in each structural member.

@inproceedings{bib_ABSO_2020, AUTHOR = {RAVI SHANKAR BADRY, Pradeep Kumar Ramancharla}, TITLE = {ABSORBING BOUNDARY CONDITIONS FOR WAVE PROPAGATION IN VISCOELASTIC MATERIALS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Radiating boundary conditions are essential in the numerical analysis of infinite domains such as dynamic SoilStructure-Interaction analysis. Local absorbing boundary conditions proposed by Lysmer and Kuhlemeyer (1969) are widely used in SSI analysis. These boundary conditions are developed based on the wave propagation in elastic materials. However, almost all soil materials exhibit viscoelastic properties. Badry and Ramancharla (2018) proposed the Absorbing Boundary Conditions for wave propagation in viscoelastic materials (VABC). The VABC conditions were developed from the original Absorbing Boundary Conditions (ABC) by including a spring in addition to the dashpot. In fact, these boundary conditions are inefficient when the waves impinge other than normal direction. In this paper, the radiating boundary conditions are modelled using VABC and ALID (Absorbing Layers by Increase in Damping) together to include the advantages of both the boundary conditions and to overcome the drawback of ABC on angle incidence. A detailed numerical analysis is carried out to verify the boundary conditions. The efficiency of the proposed method has been verified for both 1D and 2D wave propagation problems. The efficiency on angle incidence is verified using 2D plane strain model response through spatial Fourier Transformation. The study concludes that the proposed method is simple and reliable method for modelling radiating boundary conditions. Keywords: Local Absorbing Boundaries, Viscoelastic wave propagation, Rayleigh damping, Soil-Structure interaction, Absorbing Layers by Increase in Damping (ALID)

@inproceedings{bib_Eart_2020, AUTHOR = {Pradeep Kumar Ramancharla, C.V.R. Murty}, TITLE = {Earthquake Disaster Risk Index – A Simple Method for Assessing Relative Risk in a Country}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

UN World Conference on Disaster Risk Reduction held in 2015 at Sendai, Japan, reiterated the need for substantial reduction in loss of life and property. Thus, assessing disaster risk and identifying key items for risk mitigation are in focus. Assessment of disaster risk is a multidisciplinary effort, which includes expected tangible physical loss, such as collapse and damage to built environment. In countries with limited resources, prioritizing risk reduction effort across the different parts of the country needs a quantitative (yet simple) approach to bring objectivity into the decision-making process. This paper presents a simple method, called Earthquake Disaster Risk Index (EDRI), for estimating relative earthquake risk across the different regions in a country; it uses three major constituents of risk, namely Hazard, Exposure and Vulnerability. Hazard is taken as the acceleration hazard specified in the national earthquake design standard, Exposure as per the permitted occupancy in the Local Municipal Byelaws, and Vulnerability through a Level 2 Detailed Qualitative Assessment of buildings built in the Town or City (with penalty points for missing features of earthquake resistance compared to an Ideal Building). First, the EDRI of a Town or City is estimated for each typology of building in the Town or City, and then the net EDRI of the Town or City is obtained as a weighted average of the EDRI of each typology of buildings using the number of buildings of each typology present in the city. The EDRI of a city so estimated can be compared with that of another city. Also, disaggregation of risk through its three major constituents of EDRI will increase awareness of the factors which contribute to risk – from expected intensity of earthquake ground shaking, to exposure of people in each building type, to vulnerability of each building typology. The exercise can be undertaken at a large scale across the country. Policy Makers of a prefecture or a state in a nation will find the results of EDRI to be a useful tool for prioritising allocation of earthquake risk mitigation resources and effort across Towns and Cities.

@inproceedings{bib_VARI_2020, AUTHOR = {Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {VARIATION OF GROUND MOTION CHARACTERISTICS IN PARALLEL AND NORMAL DIRECTIONS IN NEAR-FAULT REGION: A CASE STUDY ON 1999 CHI-CHI EARTHQUAKE}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Structural engineering involves clear understanding of characteristics of ground motion used in the design of structures to identify the critical aspects of their behavior. Peak amplitude of response (a, v, or d), predominant frequency and duration of strong ground motion are the most important parameters of ground motion that are required for this purpose. These parameters are influenced by the source, path and site conditions. However, it is also found that for the same distance these characteristics are highly sensitive to the fault direction and the side on which the site lies i.e., hanging wall or foot wall. In this paper, a case study is performed to understand the influence of fault direction and location of site on the characteristics of the ground motion. For this purpose, 371 ground motions recorded during 1999 Chi-Chi, Taiwan earthquake are selected. Initially, these ground motions were arranged in terms of fault parallel and fault normal direction and also according to distance from the fault. Later, ground motion characteristics were obtained using standard procedures. From the above, it was found that, in the near-fault region, PGA and PGV on the hanging wall are higher by at-least 20% than that on the footwall. From this observation, the near-fault region can be defined not by using the distance from the fault, but by observing the ratio of PGA values in fault normal and parallel directions. This method of estimating the near-fault region is reliable because the hanging wall effect is caused only due to the inclined dip-angle of the fault which is inevitable in most of the thrust and normal faults. Keywords: Hanging wall effect; PGA; Thrust faults; Fault Normal; Fault Parallel

@inproceedings{bib_COMP_2020, AUTHOR = {Ganesh Kumar Ramancharla, Pradeep Kumar Ramancharla}, TITLE = {COMPATIBILITY OF CONSTRUCTION MATERIALS IN DIFFERENT GEO-CLIMATIC REGIONS OF INDIA FOR EARTHQUAKE SAFETY}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

India is a country which is prone to earthquakes. Many great earthquakes of the world have occurred in India, but still safe earthquake construction practices are not popular yet. This is mainly due to lack of awareness regarding earthquake problems and also earthquake safety features of buildings. On the other hand, India is a country with many diversified building technologies where there is a large variation in selection of building materials and building technologies. Over the ages, building materials and technologies were linked to the geo-climatic conditions of the area and the same is evident from census data of the country. However, during past earthquakes, many buildings collapsed due to the lack of earthquake resistant features in these buildings, resulting in huge life loss. This paper is an attempt to identify the critical earthquake resistant elements in each building typology which is popular in a given region. The same is demonstrated by taking two building typologies i.e., framed buildings and load bearing structures in four different regions i.e., hilly region, plain region, snowfall region and heavy rainfall region. From the above, it is clear that each housing typology can be made earthquake resistant by understanding the role of critical elements and by not deviating from standard design which is safe as well as compatible with geo-climatic conditions of the region.

@inproceedings{bib_FORE_2020, AUTHOR = {Swapnil Nayan, Prakke Bharat, Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {FORECASTING OF EARTHQUAKE USING RECURRENT NEURAL NETWORK}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Estimating the time, location and the size of an earthquake event using neural networks is an emerging technology. Present study aims to predict the near future earthquake events in each of the regions partitioned as clusters of epi-central locations of earthquakes related to Indian subcontinent. K-means clustering algorithm is applied to develop a catalogue of earthquake epicenters. Two approaches are considered for the purpose of forecasting. In the first approach regions obtained as clusters are considered as the area sources. The distribution of time series of (temporal distribution) events are divided into five time periods viz., 15 days, 30 days, 60 days, 90 days and 180 days. The accuracy of forecasting a magnitude for the next time period is studied using application of Recurrent Neural Network In the second approach the seismic data of each cluster is further grouped into three categories of magnitude viz., minor (≤ 4 Mw), moderate (between 4 Mw and 6 Mw) and strong (> 6 Mw). Accuracy of forecasting for each of the group belonging to the clusters is computed considering the same five time periods. The epicentral locations represented as latitude and longitude is the inputs for recurrent neural network. The results show that accuracy of second approach is significantly more than first approach. Finally, an attempt has been made to compare the accuracy level of Recurrent Neural Network method with the accuracy level of Gutenberg Richter law in predicting the earthquakes for future 60 days. It has been observed that Gutenberg-Richter law poorly forecasts near future earthquake. Keywords: Recurrent Neural Network; Earthquake forecasting, Clustering

@inproceedings{bib_PERF_2020, AUTHOR = {Niharika, Pradeep Kumar Ramancharla}, TITLE = {PERFORMANCE ASSESSMENT OF UPPER STORIES IN AN OPEN GROUND STOREY BUILDING WITH RETROFITTED GROUND STOREY}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Open ground storey buildings are quite popular in India due to availability of parking space and high commercial value of the land. However, these open ground storey buildings become first victims during earthquake ground shaking. The same is evident from the collapse and huge damage in ground story columns during past earthquake events. This led to a huge loss of life and property. Hence, there is an urgent need to take up retrofit activities of open ground storey buildings. There were some instances where retrofit activities were taken up on open ground story buildings. However, the performance of the building was not tested after ground storey retrofit. To build confidence among the general public, there is a need to demonstrate that the retrofitted buildings not only save lives but also resist earthquake with minimum damage. This paper is an attempt to demonstrate the same. In this paper, a case study of G+5 open ground storey building has been taken and nonlinear static pushover analysis (POA) is performed to obtain capacity curve. Later, the building is retrofitted in its ground/first storey and again capacity curve is obtained using the POA. It is found that the performance of the building significantly improved. However, from the hinge formation pattern, it is observed that the damage has propagated to the second storey. To improve the performance further, the second storey is also retrofitted and POA is performed again. Further, as per the damage propagation to upper stories, retrofitting is done to respective stories. It is found from the hinge pattern and capacity curves that in retrofitted buildings, capacity increased up to a certain storey and after that no increment in capacity was observed. It is concluded from the study that retrofitting of open ground storey building does not mean retrofitting of only ground storey but all such columns/stories where damage is getting distributed after the retrofit of open ground storey.

@inproceedings{bib_RESP_2020, AUTHOR = {Bendapudi V. Haritha Pallavi, Pradeep Kumar Ramancharla}, TITLE = {RESPONSE OF GRAVITY DAMS AGAINST STRONG EARTHQUAKE GROUND MOTIONS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Dams are extremely important lifelines of a country. They aid in the growth of the economy. The large-scale devastation due to an earthquake can generate irreversible losses. 2% of the dam failures all around the world take place due to earthquakes. Earthquakes not only cause immediate damage but are also capable of weakening the structure by decreasing its resistance against further damages. In this work, we study the effect of strong ground motion earthquakes on concrete gravity dams. The strong ground motions lying within shallow depths are felt powerfully by the dams, since the high frequency waves are not filtered. This causes more damage to the dam as there is a high probability of resonance in higher modes, a result of the high frequency content in the ground motion. 5 strong ground motions in the Indian Subcontinent have been selected and applied on the Koyna dam which was constructed in the year 1963. 2D analysis of the dam has been performed in standard software. Qualitative analysis of dams shows that there are 3 regions which are most susceptible to damage within a dam cross-section i.e., neck, body and the heel of the dam. In this paper, the displacement of crest and the formation of tensile stresses at the 3 zones - neck, body, heel of the dam due to these 5 strong ground motions is analyzed. The point of highest tensile stress is most susceptible to damage and failure in the face of an earthquake. When the structure is exposed to the ground motions, under normalized peak ground accelerations (PGAs), the structure behaves differently based on the effect of the frequency content of the input signal. By Normalizing the PGA of the ground motion, we grasp an idea of the effect of frequency content on the dam structure. Keywords: Gravity dam; Stress analysis; Qualitative failure analysis; Frequency Content; Deterministic Analysis

@inproceedings{bib_SEIS_2020, AUTHOR = {Niharika Peddaprolu, Pradeep Kumar Ramancharla}, TITLE = {SEISMIC PERFORMANCE COMPARISION OF COMMERCIAL BUILDING STRENGTHENED USING RC COLUMN JACKETING ON 2 AND 4 FACES}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

In India due to rapid economic development and establishment of new companies, many existing buildings were given permissions to raise the number of floors. This addition of new floors to the existing building will increase the loads on the columns which may not be designed for the additional load. Therefore, such columns need to be strengthened to carry the additional loads. RC jacketing is the most preferred strengthening technique to increase the load carrying capacity of the existing building. In this paper, comparison of two RC buildings i.e., One with columns strengthened only on 2 faces and another with columns strengthened on all four sides with RC jacketing is presented. In 2-face RC jacketing, U shape stirrups are used and for 4-face jacketing closed stirrups are used. Behavior of columns strengthened on all four sides using RC jacketing is more satisfactory in the case of immediate occupancy. In case of high seismic zones under cyclic loading, the seismic performance of RC jacketed columns on 2 sides is not desirable for immediate occupancy.

@inproceedings{bib_TORS_2020, AUTHOR = {Rahul Suresh Vishwakarma, Pradeep Kumar Ramancharla}, TITLE = {TORSIONAL BEHAVIOUR OF HILL SLOPE BUILDINGS: A CASE STUDY ON DIFFERENT PLAN ASPECT RATIOS AND SLOPE ANGLES}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Buildings on hill slopes are highly vulnerable due to its less resistive lateral load capacity. This type of buildings are unsymmetrical and are of in irregular configuration. There are variations in the column height which gives eccentricity to the structure as the center of mass and center of rigidity doesn’t coincide. This irregularity leads to its torsional behavior and gives us the necessity for analyzing these buildings for its base conditions and its behavior by changing its plan configuration. This paper contain the calculation of Twist which is an effective parameter to decide the behavior of the building, Axial forces on the members that can lead to collapse in the structure and about the twist variation with change in the aspect ratio so that we can know the suitability of the configuration of the building. The building on hill slopes does not behave similar to the buildings which are on plane ground. Change in the Aspect ratio means changing the length of the building in ridge direction. Changing the length in valley direction will disturb the load path of gravity load for each and every change in the structure and after some increment of the length in valley direction will fail the structure for its gravity load path. So we can’t play with the length of the building along the valley direction but changing the length along ridge direction does not effect that much to the load path of gravity load and we can obtain a best aspect ratio of the structure for that region. Keywords: Twist, Axial forces, Slope of the ground

@inproceedings{bib_Comp_2020, AUTHOR = {Niharika, Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {Comparison of Building performance with partial Retrofitting and full Retrofitting }, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2020}}

Buildings damaged in past earthquakes have exemplified the poor performance of reinforced concrete moment resisting frame (RC MRF) buildings due to inadequate design and wrong construction practices. The only way to avoid damage to existing buildings is to retrofit them. There is a large stock of RC MRF buildings constructed as per old Indian standards. With the latest revisions in codal provisions, these buildings are considered to be inadequately designed. Therefore, a large stock of existing buildings needs to be retrofitted. However, retrofitting of houses is not a common practice among the general public in India. To encourage retrofitting among the general public, the efficacy of retrofitting needs to be proven with the well-laid process. In this paper, a case study is done to understand the performance of G+5 storey RC MRF precode building after partial and full column retrofitting. Pushover Analysis (POA) is performed to obtain the capacity of the precode building. The capacity is compared with the seismic demand of that area to decide whether retrofitting is required or not. Initially, ground storey columns are retrofitted and POA is performed to study the damage distribution and obtain the updated capacity curve. It is observed that damage shifted to the first storey. Further, the first storey columns are retrofitted and POA is performed again. From the hinge mechanism, it is observed that the damage propagated to the second storey. Further, the second storey columns are retrofitted and POA is performed again to obtain updated capacity and

@inproceedings{bib_Comp_2020, AUTHOR = {Niharika, Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {Comparison of Building performance with partial Retrofitting and full Retrofitting}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2020}}

Buildings damaged in past earthquakes have exemplified the poor performance of reinforced concrete moment resisting frame (RC MRF) buildings due to inadequate design and wrong construction practices. The only way to avoid damage to existing buildings is to retrofit them. There is a large stock of RC MRF buildings constructed as per old Indian standards. With the latest revisions in codal provisions, these buildings are considered to be inadequately designed. Therefore, a large stock of existing buildings needs to be retrofitted. However, retrofitting of houses is not a common practice among the general public in India. To encourage retrofitting among the general public, the efficacy of retrofitting needs to be proven with the well-laid process. In this paper, a case study is done to understand the performance of G+5 storey RC MRF precode building after partial and full column retrofitting. Pushover Analysis (POA) is performed to obtain the capacity of the precode building. The capacity is compared with the seismic demand of that area to decide whether retrofitting is required or not. Initially, ground storey columns are retrofitted and POA is performed to study the damage distribution and obtain the updated capacity curve. It is observed that damage shifted to the first storey. Further, the first storey columns are retrofitted and POA is performed again. From the hinge mechanism, it is observed that the damage propagated to the second storey. Further, the second storey columns are retrofitted and POA is performed again to obtain updated capacity and

@inproceedings{bib_FORE_2020, AUTHOR = {Swapnil Nayan, Prakke Bharat, Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {FORECASTING OF EARTHQUAKE USING RECURRENT NEURALNETWORK}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Estimating the time, location and the size of an earthquake event using neural networks is an emerging technology. Present study aims to predict the near future earthquake events in each of the regions partitioned as clusters of epi-central locations of earthquakes related to Indian subcontinent. K-means clustering algorithm is applied to develop a catalogue of earthquake epicenters. Two approaches are considered for the purpose of forecasting. In the first approach regions obtained as clusters are considered as the area sources. The distribution of time series of (temporal distribution) events are divided into five time periods viz., 15 days, 30 days, 60 days, 90 days and 180 days. The accuracy of forecasting a magnitude for the next time period is studied using application of Recurrent Neural Network In the second approach the seismic data of each cluster is further grouped into three categories of magnitude viz., minor (≤ 4 Mw), moderate (between 4 Mw and 6 Mw) and strong (> 6 Mw). Accuracy of forecasting for each of the group belonging to the clusters is computed considering the same five time periods. The epicentral locations represented as latitude and longitude is the inputs for recurrent neural network. The results show that accuracy of second approach is significantly more than first approach. Finally, an attempt has been made to compare the accuracy level of Recurrent Neural Network method with the accuracy level of Gutenberg Richter law in predicting the earthquakes for future 60 days. It has been observed that Gutenberg-Richter law poorly forecasts near future earthquake.

@inproceedings{bib_Sepa_2020, AUTHOR = {VELANI PULKIT DILIP, Pradeep Kumar Ramancharla}, TITLE = {Separation distance between two adjacent buildings a case study (Clause 7.11. 3, Is 1893: 2016)}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2020}}

Construction of buildings without keeping enough setback from plot boundary is very common practise in India. This lead to very closely spaced buildings with practically zero or few mm gap between them. The intension behind this is to utilize the maximum plot area, without knowing the consequences of damage due to pounding during moderateto-severe earthquake shaking. In this study, an attempt is made to check the adequacy of separation distance clause of IS 1893: 2016 and also a comparison is made with similar clauses in international codes of practise. For this purpose, four low to mid-rise RC buildings located in seismic zone IV were designed as per IS 456: 2000 and IS 1893: 2016. These buildings are assumed to be closely spaced with each other, in pair of two, for four different cases. Further, the linear and non-linear time history analysis (NLTHA) were carried out by considering ground motion time histories of three moderate earthquakes recorded in India. From the study, it was found that the separation distance clauses prescribed in IS 1893-2016 are on conservative side.

@inproceedings{bib_Effe_2020, AUTHOR = {Mangeshkumar R. Shendkar, Sasankasekhar Mandal, Pradeep Kumar Ramancharla}, TITLE = {Effect of lintel beam on response reduction factor of RC-infilled frames}, BOOKTITLE = {Current Science}. YEAR = {2020}}

In this study, a three-dimensional, four-storied, reinforced concrete (RC) building is designed for seismic zone-IV and seismically evaluated for different infill configurations along with consideration of openings in infills to develop a realistic model. Four models are considered, ie model I (full RC-infilled frame without lintel beam), model II (bare frame without lintel beam), model III (full RC-infilled frame with lintel beam) and model IV (bare frame with lintel beam). In this study, we have evaluated the effect of lintel beams on response reduction factor of the frame structure. The nonlinear static adaptive pushover analysis has been done using Seismostruct program. In seismic design, the response reduction factor (R-factor) reduces from the elastic to inelastic strength. The R-factor is one of the design tools to show the level of inelasticity in a structure and so it has significant importance in the earthquake engineering field. The response reduction factor mainly consists of ‘ductility reduction factor’and ‘over strength factor’, which are evaluated from static adaptive pushover analysis. Ultimately the response reduction factor is obtained for the building and compared with the value recommended by IS 1893 Part-1 (2016). The results depict that the

@inproceedings{bib_Eval_2020, AUTHOR = {Singh Prakash Abhiram, Pradeep Kumar Ramancharla}, TITLE = {Evaluation of Response Reduction Factors for Different Retrofitting Techniques Applied to Open Ground Storey Building}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2020}}

@inproceedings{bib_ESTI_2020, AUTHOR = { Chenna Rajaram, Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {ESTIMATION OF SEISMIC HAZARD FOR KATHMANDU, NEPAL AND ADJACENT REGIONS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

An earthquake Mw7.8 occurred on 25 April 2015 in a seismically dominant area of Nepal. No major earthquakes (>Mw7.0) were recorded in the past two decades, though Nepal is one of the active seismic regions in the world. The combined effect of the main event and the aftershocks, which are temporally distributed over 40 days, has led to a huge devastation, killing thousands of people in the epi-central area. A complete seismic catalog and influencing parameters such as type of fault, epi-central/hypo-central distance, type of soil are required for a region to assess seismic hazard scenario. The seismic hazard can be represented in terms of Peak Ground Acceleration (PGA), which is the most widely used parameter in strong motion studies. The main objective of this paper is to understand the characteristics of ground motion of the 2015 Nepal earthquake. Since the available ground motion records are limited, an attempt has been made to generate ground motion records using a modified semi-empirical approach. Contour maps of PGA and intensity have also been generated. It is observed that around 22% of buildings experienced an intensity of VI on MMI scale at Bageswari mandal. A few buildings have experienced an intensity of VII in Thankot, Seuchatar, Satikhel, Mahadevathan, Indrayani, Chhaimale, and Balambu.

@inproceedings{bib_QUAN_2020, AUTHOR = {Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {QUANTIFICATION OF DAMAGE USING HINGE PATTERN IN RC MOMENT RESISTING FRAME BUILDINGS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Damage index models are used for quantification of damage in any numerical model of a building. While using any particular damage model there is high possibility that it might give similar result for two identical structures, each having different attributes. So, though currently available damage index models precisely quantify damage in the structure but fails to identify the reason or attributes/irregularities present in it. Therefore, for quantitative assessment, a unique aspect should be used which will depend on structural as well as architectural features. This paper presents new method for quantification of damage for reinforced concrete (RC) moment resisting framed (MRF) structures using the pattern of hinge formation in structure when it is subjected to a monotonic loading. A two-dimensional RC MRF structures with different building irregularities were modeled. As a primary step to estimate the damage from the pattern of hinge formation, it is necessary to understand and study the relation between damage and hinge pattern. For this purpose, energy-based damage index model is used. The relation between damage index and pattern of hinge formation is studied with the help of regression analysis. A multiple regression analysis is performed taking damage index as dependent variable and the number of hinges formed in each damage state as independent variables. The paper also discusses two different approaches for regression analysis determining the corresponding coefficients. The regression analysis resulted in an equation which can approximately quantify the damage in the structure using total number of hinges formed in each

@inproceedings{bib_TORS_2020, AUTHOR = {Rahul Suresh Vishwakarma, Pradeep Kumar Ramancharla}, TITLE = {TORSIONAL BEHAVIOUR OF HILL SLOPE BUILDINGS: A CASE STUDY ON DIFFERENT PLAN ASPECT RATIOS AND SLOPE ANGLES}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Buildings on hill slopes are highly vulnerable due to its less resistive lateral load capacity. This type of buildings are unsymmetrical and are of in irregular configuration. There are variations in the column height which gives eccentricity to the structure as the center of mass and center of rigidity doesn’t coincide. This irregularity leads to its torsional behavior and gives us the necessity for analyzing these buildings for its base conditions and its behavior by changing its plan configuration. This paper contain the calculation of Twist which is an effective parameter to decide the behavior of the building, Axial forces on the members that can lead to collapse in the structure and about the twist variation with change in the aspect ratio so that we can know the suitability of the configuration of the building. The building on hill slopes does not behave similar to the buildings which are on plane ground. Change in the Aspect ratio means changing the length of the building in ridge direction. Changing the length in valley direction will disturb the load path of gravity load for each and every change in the structure and after some increment of the length in valley direction will fail the structure for its gravity load path. So we can’t play with the length of the building along the valley direction but changing the length along ridge direction does not effect that much to the load path of gravity load and we can obtain a best aspect ratio of the structure for that region.

@inproceedings{bib_ABSO_2020, AUTHOR = {RAVI SHANKAR BADRY, Pradeep Kumar Ramancharla}, TITLE = {ABSORBING BOUNDARY CONDITIONS FOR WAVE PROPAGATION IN VISCOELASTIC MATERIALS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Radiating boundary conditions are essential in the numerical analysis of infinite domains such as dynamic SoilStructure-Interaction analysis. Local absorbing boundary conditions proposed by Lysmer and Kuhlemeyer (1969) are widely used in SSI analysis. These boundary conditions are developed based on the wave propagation in elastic materials. However, almost all soil materials exhibit viscoelastic properties. Badry and Ramancharla (2018) proposed the Absorbing Boundary Conditions for wave propagation in viscoelastic materials (VABC). The VABC conditions were developed from the original Absorbing Boundary Conditions (ABC) by including a spring in addition to the dashpot. In fact, these boundary conditions are inefficient when the waves impinge other than normal direction. In this paper, the radiating boundary conditions are modelled using VABC and ALID (Absorbing Layers by Increase in Damping) together to include the advantages of both the boundary conditions and to overcome the drawback of ABC on angle incidence. A detailed numerical analysis is carried out to verify the boundary conditions. The efficiency of the proposed method has been verified for both 1D and 2D wave propagation problems. The efficiency on angle incidence is verified using 2D plane strain model response through spatial Fourier Transformation. The study concludes that the proposed method is simple and reliable method for modelling radiating boundary conditions. Keywords: Local Absorbing Boundaries, Viscoelastic wave propagation, Rayleigh damping, Soil-Structure interaction, Absorbing Layers by Increase in Damping (ALID)

@inproceedings{bib_A_Ca_2020, AUTHOR = {Dasari Hima Chandan, Pradeep Kumar Ramancharla}, TITLE = {A Case Study on Modal dynamic Identification of building from Mild earthquake responses}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

In last two decades, operational modal analysis is widely used for modal identification of structures which uses ambient responses of structure for determining the modal parameters and Frequency Domain Decomposition is one of the most popular method, but seismic excitations and high damping values of structures do not satisfy the assumptions of this classical method. The dynamic modal parameters derived from earthquake responses are more reliable than those from small amplitude responses since dynamic properties of civil structures are dependent on amplitude. In recent years, a new algorithm known as refined Frequency Domain Decomposition (rFDD) is developed which uses structural response to strong ground motions that can be short in duration and is applicable for structures with light to heavy damping. The refined Frequency Domain Decomposition (rFDD) algorithm was initially developed using synthetic seismic response signals as input and later real strong motion response records were used to demonstrate the effectiveness of this algorithm for modal dynamic identification of structures under real earthquake excitations. This method is well developed to counter the problems that normally arise in modal identification and in cases of heavy damping and non-stationarity of the signal, making it lengthy and tedious to process. In this paper the main feature of this method which is Integrated Power Spectral Density matrix computation is taken and applied on mild earthquakes responses of structure. The modal parameters identified are then compared with target values obtained from classical FDD method using ambient responses and interpreted, presenting a case for usage of rFDD in simplified manner in modal dynamic identification of structures. Keywords: Operational Modal analysis, mild earthquake response, refined Frequency Domain Decomposition

@inproceedings{bib_Eart_2020, AUTHOR = {Pradeep Kumar Ramancharla, CVR Murthy}, TITLE = {Earthquake Disaster Risk Index–A Simple Method for Assessing Relative Risk in a Country}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

UN World Conference on Disaster Risk Reduction held in 2015 at Sendai, Japan, reiterated the need for substantial reduction in loss of life and property. Thus, assessing disaster risk and identifying key items for risk mitigation are in focus. Assessment of disaster risk is a multidisciplinary effort, which includes expected tangible physical loss, such as collapse and damage to built environment. In countries with limited resources, prioritizing risk reduction effort across the different parts of the country needs a quantitative (yet simple) approach to bring objectivity into the decision-making process. This paper presents a simple method, called Earthquake Disaster Risk Index (EDRI), for estimating relative earthquake risk across the different regions in a country; it uses three major constituents of risk, namely Hazard, Exposure and Vulnerability. Hazard is taken as the acceleration hazard specified in the national earthquake design standard, Exposure as per the permitted occupancy in the Local Municipal Byelaws, and Vulnerability through a Level 2 Detailed Qualitative Assessment of buildings built in the Town or City (with penalty points for missing features of earthquake resistance compared to an Ideal Building). First, the EDRI of a Town or City is estimated for each typology of building in the Town or City, and then the net EDRI of the Town or City is obtained as a weighted average of the EDRI of each typology of buildings using the number of buildings of each typology present in the city.

@inproceedings{bib_VARI_2020, AUTHOR = {Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {VARIATION OF GROUND MOTION CHARACTERISTICS IN PARALLEL AND NORMAL DIRECTIONS IN NEAR-FAULT REGION: A CASE STUDY ON 1999 CHI-CHI EARTHQUAKE}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Structural engineering involves clear understanding of characteristics of ground motion used in the design of structures to identify the critical aspects of their behavior. Peak amplitude of response (a, v, or d), predominant frequency and duration of strong ground motion are the most important parameters of ground motion that are required for this purpose. These parameters are influenced by the source, path and site conditions. However, it is also found that for the same distance these characteristics are highly sensitive to the fault direction and the side on which the site lies ie, hanging wall or foot wall. In this paper, a case study is performed to understand the influence of fault direction and location of site on the characteristics of the ground motion. For this purpose, 371 ground motions recorded during 1999 Chi-Chi, Taiwan earthquake are selected. Initially, these ground motions were arranged in terms of fault parallel and fault normal direction and also according to distance from the fault. Later, ground motion characteristics were obtained using standard procedures. From the above, it was found that, in the near-fault region, PGA and PGV on the hanging wall are higher by at-least 20% than that on the footwall. From this observation, the near-fault region can be defined not by using the distance from the fault, but by observing the ratio of PGA values in fault normal and parallel directions. This method of estimating the near-fault region is reliable because the hanging wall effect is caused only due to the inclined dip-angle of the fault which is inevitable in most of the thrust and normal faults.

@inproceedings{bib_COMP_2020, AUTHOR = {Pammi Raghu Nandan Vyas, Pradeep Kumar Ramancharla}, TITLE = {COMPARISION OF DIRECT DISPLACEMENT SEISMIC DESIGN WITH FORCE BASED DESIGN USING INDIAN STANDARDS–A CASE STUDY}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2020}}

Development of Force-based seismic design is historical, and every earthquake has thrown new challenges for already existing assumptions and principles, which helped in the evolution of force-based design. Although many of the assumptions were answered but some remained unaltered and unanswered. Hence, this paved way for developing new theories and philosophies and one such theory is Direct Displacement-Based seismic Design (DDBD). Indian Standard codes, IS 1893 and IS 13920, underwent a major revision in the year 2016, considering the latest developments in Force based design principles. Current work is an attempt to understand the performance comparison between latest IS 1893 & IS 13920 with DDBD method. Initially, three buildings ie, 3, 6 and 9 storey buildings were designed using DDBD at inter-storey drift of 4% with a performance objective to achieve “No collapse”. The spectrum developed using IS code equations does not represent ideal displacement spectrum shape and hence PGA, T and CA dependent equations are used for DDBD methodology of design. PGA of 0.36 g is used in the current study which represents the highest seismic zone in India. Later these buildings were subjected to lateral displacement using displacement-based pushover analysis method. The inelastic strength along with drifts achieved by DDBD are compared with the IS code compliant buildings. From the comparison, it was observed that inelastic strength achieved by 6, 9 storey buildings designed according to FBD are greater than the buildings designed according to DDBD at “No Collapse”. For 3 storey structure, the strength …

@inproceedings{bib_Vuln_2020, AUTHOR = {Srinagesh, D, Pradeep Kumar Ramancharla, T Seshunarayana, RK Chadha, Narender Bodige, G.Suresh, D Hima Chandan, D Hima Chandan}, TITLE = {Vulnerability assessment of a heritage structure subjected to blast-induced ground motions.}, BOOKTITLE = {Current Science}. YEAR = {2020}}

A ground-structure vibration response study was carried out at the Ramappa Temple near Warangal, Telangana, India, shaken by underground blasting undertaken at the neighbouring Devadula Lift Irrigation Project to build water tunnels. The intensities of vibrations were examined–subsurface and ground vibrations were measured using velocity meters, and shaking at the temple using accelerometers. The study concluded that high-frequency vibrations of the ground were filtered by the soft natural clay bed underneath, and vibrations at the temple structure were small and well below the levels that can cause damage to it. Here we present the scientific findings of the vibrations recorded during the blasts and their implications.

@inproceedings{bib_EFFE_2020, AUTHOR = {MANGESHKUMAR SHENDKAR, Pradeep Kumar Ramancharla, PABITRA RANJAN MAITI}, TITLE = {EFFECT OF ASPECT RATIO ON RESPONSE REDUCTION FACTOR OF RC FRAMED STRUCTURES WITH SEMI-INTERLOCKED MASONRY AND UNREINFORCED MASONRY INFILL}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2020}}

In building construction, reinforced concrete (RC) Frame structures are frequently used due to ease of construction and rapid progress of work. In this study, two types of infill’s are used ie, unreinforced masonry infill and semi-interlocked masonry infill. For the analysis purpose of infill, a double strut nonlinear cyclic model is used. The main objective of the study is to investigate the importance of interlocked brick infill in the RC frame structure. For understanding the same, nonlinear static pushover analysis is carried out on analytical models using finite element based software, SeismoStruct. The response reduction factor components such as ductility reduction factor and overstrength factors were computed from nonlinear static pushover analysis and finally, the response reduction factor is calculated for all models. The primary focus is given to numerical modeling, nonlinear behavior of brick masonry RC buildings subjected to lateral loads and calculation of the response reduction factor of'RC'infilled frames with different aspect ratios.

@inproceedings{bib_Sepa_2020, AUTHOR = {VELANI PULKIT DILIP, Pradeep Kumar Ramancharla}, TITLE = {Separation distance between two adjacent buildings a case study}, BOOKTITLE = {STRUCTURAL ENGINEERING}. YEAR = {2020}}

Construction of buildings without keeping enough setback from plot boundary is very common practise in India. This lead to very closely spaced buildings with practically zero or few mm gap between them. The intension behind this is to utilize the maximum plot area, without knowing the consequences of damage due to pounding during moderateto-severe earthquake shaking. In this study, an attempt is made to check the adequacy of separation distance clause of IS 1893:2016 and also a comparison is made with similar clauses in international codes of practise. For this purpose, four low to mid-rise RC buildings located in seismic zone IV were designed as per IS 456:2000 and IS 1893:2016. These buildings are assumed to be closely spaced with each other, in pair of two, for four different cases. Further, the linear and non-linear time history analysis (NLTHA) were carried out by considering ground motion time histories of three moderate earthquakes recorded in India. From the study, it was found that the separation distance clauses prescribed in IS 1893-2016 are on conservative side

@inproceedings{bib_Effe_2020, AUTHOR = {Mangeshkumar R. Shendkar, Sasankasekhar Mandal, Pradeep Kumar Ramancharla}, TITLE = {Effect of lintel beam on response reduction factor of RC-infilled frames}, BOOKTITLE = {Current Science}. YEAR = {2020}}

In this study, a three-dimensional, four-storied, reinforced concrete (RC) building is designed for seismic zone-IV and seismically evaluated for different infill configurations along with consideration of openings in infills to develop a realistic model. Four models are considered, i.e. model I (full RC-infilled frame without lintel beam), model II (bare frame without lintel beam), model III (full RC-infilled frame with lintel beam) and model IV (bare frame with lintel beam). In this study, we have evaluated the effect of lintel beams on response reduction factor of the frame structure. The nonlinear static adaptive pushover analysis has been done using Seismostruct program. In seismic design, the response reduction factor (R-factor) reduces from the elastic to inelastic strength. The R-factor is one of the design tools to show the level of inelasticity in a structure and so it has significant importance in the earthquake engineering field. The response reduction factor mainly consists of ‘ductility reduction factor’ and ‘over strength factor’, which are evaluated from static adaptive pushover analysis. Ultimately the response reduction factor is obtained for the building and compared with the value recommended by IS 1893 Part-1 (2016). The results depict that the R-factor values of full RC-infilled frames and bare frames with incorporation of lintel beams are higher than other frames without lintel beam. However, R-factor values of bare frames are lower than the corresponding values recommended in the BIS code.

@inproceedings{bib_Effe_2019, AUTHOR = {Pammi Raghu Nandan Vyas, Pradeep Kumar Ramancharla}, TITLE = {Effects of Vertical Ground Motions on the design of Regular RC Buildings located in seismic Zone V (Is 1893:2016 Clauses 6.3.2.1 And 6.3.3)}, BOOKTITLE = {STRUCTURAL ENGINEERING DIGEST}. YEAR = {2019}}

Recent revision of Indian standard code on earthquake resistant design suggested certain recommendations for inclusion of effects of vertical ground acceleration for design of buildings. Clause 6.3.2.1 of IS 1893 (Part 1) suggests that for non-orthogonal frames, load combinations should include 30% of earthquake load in other directions along with the direction considered and Clause 6.3.2.1.1 suggests that for orthogonal frames, full load has to be applied. Besides, clause 6.3.3 mentions that all the buildings present in seismic zone IV and V have to consider vertical ground motion effects. This results in 73 load combinations for calculating the design forces in structural members. However, the necessity to consider the effects of vertical ground motions for regular buildings, although present in seismic zones IV and V, is not verified. To verify the above clauses for regular buildings, a case study is performed on a 5 storied regular framed RC building. Using, linear static analysis, design forces in structural members for the contradicting clauses on load combinations are compared. From the study, it is concluded that 3-dimensional ground motion effects are not necessary for every building even if the building is located in seismic zone IV or V.

@inproceedings{bib_Nume_2019, AUTHOR = {RAVI SHANKAR BADRY, Pradeep Kumar Ramancharla}, TITLE = {Numerical Modelling of Radiating Boundary Conditions Combined with Modified Absorbing Boundary Condition for Viscoelastic Wave Propagation}, BOOKTITLE = {International Conference on Computational Structures Technology}. YEAR = {2019}}

Modelling the Sommerfeld radiating boundary is a major challenge appearing in the study of many engineering problems involving elastic wave propagation [1]. Particularly, in the finite element analysis of Structure-Soil-Structure-Interaction (SSSI) problems, where the soil modelling has to be truncated at a finite distance. This truncation of the model at finite boundary leads to reflection of radiating elastic waves. The reflected waves from the boundary will affect the solution and may lead to instabilities in the numerical analysis. Therefore, it is necessary to provide an artificial boundary condition that will transmit the outward propagating waves with minimum or negligible reflections. To address the radiating boundary condition problem, researchers have developed various kinds of formulations over few decades, such as: a). Local Absorbing Boundary Conditions (ABC) [2], b). Absorbing Layers techniques which includes Perfectly Matched Layers [3-4], Caughey Absorbing Layer Method (CALM) [5], Absorbing Layers by Increasing Damping (ALID) [6] c). Boundary element method [7], and d). Infinite elements [8-10]. ABC corresponds to the situation where the boundary is supported on infinitesimal dash-pots oriented normal and tangential to the boundary. Though these boundary conditions are very simple, the major drawback is they are inefficient when the wave impinges the boundary in inclined direction. The key property of a PML that distinguishes it from an ordinary absorbing material is that it is designed such that the propagating waves incident upon the PML from a bulk medium do not reflect on the interface. The CALM consists of defining the absorbing layers at the boundaries of the elastic medium under consideration but requires many absorbing layers which requires much computational time. The objective of this study is to present a method for radiating boundary conditions by using modified ABC to take the effect of viscous damping combining with ALID

@inproceedings{bib_Resp_2018, AUTHOR = {Mangeshkumar Shendkar.R, Pradeep Kumar Ramancharla}, TITLE = {Response Reduction Factor of RC framed structures with Semi-interlocked masonry and unreinforced masonry infill}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2018}}

In building construction, RC frame structure are frequently used due to ease of construction and rapid progress of work. Generally these frames are filled by masonry in fill panel. However, during past earthquakes it was found that the performance of of such type of structures significantly depends on out-of-plane behavior of infill panel wall. In this study two type of infills are used i.e, unreinforced masonry infill and semi-interlocked masonry infill. For analysis purpose of infill, double strut nonlinear cyclic model is used. The main objective of the study is to investigate the importance interlocked brick infill in RC frame structure. For R factor components such as ductility reduction factor and over strength factors were computed from nonlinear static pushover analysis and finally response reduction factor is calculated for all models. In this work, primary focus is given to numerical modeling and nonlinear behavior of brick masonry building subjected to lateral loads and calculation of response reduction factor of RC infilled frame

@inproceedings{bib_Loca_2018, AUTHOR = {RAVI SHANKAR BADRY, Pradeep Kumar Ramancharla}, TITLE = {Local absorbing boundary conditions to simulate wave propagation in unbounded viscoelastic domains}, BOOKTITLE = {Computers and Structures}. YEAR = {2018}}

In this paper, Local Absorbing Boundary Conditions are presented for wave propagation through the viscoelastic media. This method is an extension of Local Absorbing Boundary Condition (ABC) proposed by Lysmer and Kuhlemeyer (1969). The proposed method does not converge for Kelvin type of viscoelastic materials but converges for Maxwell type of viscoelastic material model. This method is verified with 1D and 2D finite element models using explicit solver and the accuracy is compared with standard solutions. This study concluded that better responses can be obtained for the viscoelastic wave propagation using present approach when compared with traditional Local Absorbing Boundary Conditions. This study also concluded that the proposed method is suitable for low to medium viscous damping materials. For high viscous materials, the proposed method can be applied to transient wave propagation problems.

@inproceedings{bib_Dama_2018, AUTHOR = {Pradeep Kumar Ramancharla, Rajaram Chenna}, TITLE = {Damage assessment due to pounding between adjacent structures with equal and unequal heights}, BOOKTITLE = {Journal of Civil Structural Health Monitoring}. YEAR = {2018}}

Structural pounding may occur between two structures or at different parts of the same building during ground motions. Among all the structural damages, structural pounding has been commonly observed during several earthquakes in the past, which have lead to minor damage till complete collapse of the structure. The main focus of this paper is to study pounding responses and impact effects on structures subjected to ground motions. It is observed from the study that the response of stiff structure is more than flexible structure at dominant period of ground motion, irrespective of equal and unequal heights. If the structures vibrate at a non-dominant period of ground motion, then the response of flexible structure is observed more than the stiff structure.

@inproceedings{bib_Infl_2018, AUTHOR = {Mangeshkumar Shendkar, Pradeep Kumar Ramancharla}, TITLE = {Influence of opening in infill on R factor of RC Infilled frame structures}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2018}}

This paper is concerned with the study of effect of opening in infills on RC framed structures. Reinforced concrete buildings with masonry infill walls have been widely constructed for commercial, industrial, buildings. In this paper presents the results of analytical program showing behaviour of frames with different masonry infill i.e semi-interlocked masonry & Unreinforced masonry. The effect infill opening on seismic response of frame buildings were evaluated. A nonlinear static analysis has been carried out on different model frames by using finite element analysis software, seismostruct. The results obtained show that calculation of response reduction factor of RC infilled frames with & without opening on infill.

@inproceedings{bib_A_Co_2018, AUTHOR = {RAVI SHANKAR BADRY, Maruthi Kotti, Pradeep Kumar Ramancharla}, TITLE = {A Comparative Study of Absorbing Layer Methods to Model Radiating Boundary Conditions for the Wave Propagation in Infinite Medium}, BOOKTITLE = {International Journal of Engineering and Technology}. YEAR = {2018}}

Radiating boundary condition is an important consideration in the finite element modelling of unbounded media. Absorbing layer techniques such as Perfectly Matched Layers (PML) and Absorbing Layers by Increasing Damping (ALID) becoming popular as they are efficient in absorbing outward propagating waves energy. In this study, a comparative analysis has been carried out between PML and ALID+VABC (Absorbing Boundary conditions for Viscoelastic materials) methods. The methods are analyzed using LSDYNA explicit solver and the efficiency is compared with standard solutions. The study concluded that PML requires less number of elements to model the boundary conditions when compared with ALID+VABC. But PML requires a smaller element length which increases overall computational time. Both the methods are efficient in absorbing the wave energy. However, PML requires additional implementation cost to solve the complex equations.

@inproceedings{bib_WEB__2017, AUTHOR = {ANUJ AGRAWAL, Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {WEB APPLICATION FOR VULNERABILITY ASSESSMENT}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

In the aftermath of 2015 Gorkha Earthquake in Nepal the challenging task was to classify structural damage; for further consideration of the building for living purposes. Manual classification of such a large number of building stock is tedious job in terms of collecting and maintaining data, particularly from the point of view of using the same for further planning purposes. Hence a web based application will make the job simple and easy for the surveyor as they will fill the details from the application and get the damage state of the building and know whether or not the building is safe for living and maintain the record of their decision. The other important feature of this application is it also does the pre-earthquake assessment of the building; thus it evaluates the state of the building before an earthquake through which occupants will know whether it safe or not to live in a particular building and also the improvements required from overall safety point of view. In this paper, description of the web application is given with some case studies. Post-earthquake assessment is done for two types of buildings which is quite common i.e., Reinforced Concrete Building and Brick Masonry Building. Pre-earthquake assessment is done in three parts, first part is Detail Visual Assessment of building based on BMTPC form and second part is Simplified Quantitative Assessment and third one is Detail Qualitative Assessment

@inproceedings{bib_Auto_2017, AUTHOR = {Swajit Singh Goud, Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Automatic Building Segmentations from LiDAR data Using Shape Plane Clustering}, BOOKTITLE = {Asian Conference on Remote Sensing}. YEAR = {2017}}

Current methods of building segmentation from LiDAR depends on extraction of roof planes to segment the buildings. In our work, we propose a new method to extract buildings using the wall facades. The motivation of using wall facades is based on the rise of terrestrial LiDAR compared to aerial LiDAR. The shape property is the most important information obtained from a LiDAR file. We try to use this shape property from the LiDAR file to segment buildings from the given scene. In the algorithm, the non-ground return points parallel to a facade of the potential building are combined to form multiple slices. These slices are parallel to the facade of a potential building. These slices are then merged based on the shape similarity and proximity to generate the footprint of the building. After generating the footprint of the building, we can also reconstruct the 3D model of the given building. The algorithm was tested both on simulated synthetic data containing different buildings and real world benchmark datasets. The results show complete segmentation of buildings from the synthetic datasets and promissory results from the real world datasets. The algorithm proposed is versatile in nature and can be easily adapted to different datasets with minimal modifications and tweaking. Existing works involve the use of secondary datasets like satellite images, orthophotos etc in order to aid in segmentation. Our work uses only the LiDAR data and no other secondary data to identify the buildings from the scene. Demonstration have been shown to segment partial buildings in a given scene as well. Thus, the novelty of the proposed work is non-dependence on any other form of data required except LiDAR. The applications of segmenting buildings from a given LiDAR scene can be used in urban planning, resource management and monitoring tasks.

@inproceedings{bib_WEB__2017, AUTHOR = {ANCHAL PANDEY, Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {WEB APPLICATION FOR GENERATION OF SHAKE MAP: A CASE STUDY ON VIJAYAWADA CITY, INDIA}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

Strong earthquakes cause a great damage to buildings and other infrastructure. It is difficult to get an overview of the situation immediately after an earthquake, to facilitate the initiation of appropriate emergency and rescue measures. Shake map provides early information on the intensity of ground shaking in a location. This data will be useful to help authorities and rescue workers for planning their work. For the purpose of study, Vijayawada city, India has been selected to generate shake map. Peak ground accelerations (PGA) are generated using ground motion prediction equations (GMPE) and the shaking intensities are also estimated for Vijayawada city. A tool for shake map has been generated using php applications. Map generation is automatically triggered by any earthquake in the vicinity of Vijayawada region and the map will be available for the public and government for post-earthquake decision making.

@inproceedings{bib_Vuln_2017, AUTHOR = {CHENNA RAJARAM, Pradeep Kumar Ramancharla, AJAY PRATAP SINGH, KAPIL MOHAN, BAL KRISHNA RASTOGI}, TITLE = {Vulnerability Assessment of Marine Structures: A Case Study on Jetty}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2017}}

etties are one of the most important structures in the coastal area, which can be used for transporting large quantities of goods and raw materials from one place to the other. Their functionality is very much essential because they are lifeline structures of the country. It is observed during the past earthquakes that jetties have been damaged even under mild shaking. Damaged and unserviceable jetties cause delay of export and import business. It directly affects the economy of particular region in terms of business, employment and growth. This clearly indicates the need to design these facilities so that they can withstand natural disasters particularly earthquakes and tsunamis. In this paper, a study has been carried out to find out the damage (D) to the Jetty. The Jetty is modeled using 2D Applied Element Method (AEM) to perform damage analysis of structure. Pushover analysis is done to get base shear vs roof displacement of building using displacement control method. Using the dissipated energy approach, damage is quantified at every displacement level and normalized to 1. A fragility curve has been developed to quantify the damage of Jetty with respect to different peak ground accelerations. The damage values were calculated for the PGA values of KHF Mandvi, NKF Jodiya and KMF Jhangi and found that the Jetty got light damage (D= 0.2), and moderate damage (D= 0.38 and 0.42) respectively.

@inproceedings{bib_Corr_2017, AUTHOR = {SREERAMA AJAY KUMAR, Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Correlation between rapid visual survey score and possible damage of a building}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2017}}

In recent past due to rapid growth of Indian cities, there is a tremendous increase on housing industry, especially in seismic Zone IV & V. As most of these constructions are without earthquake resistant measures, the built environment in these zones has been found seismically vulnerable. Detailed seismic vulnerability evaluation is a technically complex and expensive procedure and can only be performed on a limited number of buildings. The present paper highlights the use of Rapid visual screening (RVS) method for seismic assessment of reinforced concrete (RC) buildings in Himachal Pradesh state. A RVS survey has been carried out on 1540 RC buildings, out of which 6 buildings are selected for detailed analysis. The selected buildings are modeled and analyzed through numerical approach. A correlation graph has been constructed between peak ground acceleration (PGA) and, RVS, indicating different damage states of a building. Around 80% of RC buildings located in Zone V of Himachal Pradesh will suffer moderate damage and around 73% of RC buildings located in Zone IV will suffer slight damage in the event of earthquake with PGA prescribed as per IS 1893.

@inproceedings{bib_DETE_2017, AUTHOR = {Neelima Patnala, CHENNA RAJARAM, Pradeep Kumar Ramancharla, D Srinagesh}, TITLE = {DETERMINATION OF GEOPHYSICAL PARAMETERS OF HIMALAYAN REGION}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

Earthquake resistant design of structures requires the knowledge of quantified seismic hazard. To quantify the seismic hazard, Peak Ground Acceleration (PGA) is used for design procedures. The maximum possible PGA of a particular region depends on seismic parameters like magnitude, hypocentral distance, type of soil etc. Though it can be obtained by observing the past seismic events, it is more realistic to relate it with the parameters that influence it. Due to high seismic activity at the Himalayan region, this paper is aimed at developing a Ground Motion Prediction Equation (GMPE) for this region. For this purpose, two sets of 168 earthquakes (2.5-7.2 Mw) have been selected that are recorded at different stations within 500 km radius along the Himalayan belt. A statistical analysis is carried out on both sets separately based on the relation of PGA with magnitude, hypocentral distance and the type of soil. New GMPE equations have been proposed. The same are compared with the existing GMPE for the same region and seismically similar regions.

@inproceedings{bib_New__2017, AUTHOR = {Pulkit Velani, Pradeep Kumar Ramancharla}, TITLE = {New empirical formula for fundamental period of tall buildings in India by ambient vibration test}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

With the announcement of smart cities, construction of tall buildings is booming in India. There are quite a few codes for tall buildings and many of them have shortcomings in addressing the parameters for seismic design. One such parameter is the fundamental natural period of tall buildings. The expression of the fundamental period is originally developed based on Californian earthquakes and adopted by many seismic codes around the world; including current, Indian seismic code IS 1893: 2002. This paper aims to study the reliability of empirical expression of the fundamental period for tall buildings in India. For this purpose, ambient vibration tests have been carried out for 21 RC buildings, located in Mumbai and Hyderabad cities, by placing vibration sensor on topmost accessible floor. The measured periods have been compared with the code provisions. It is found in the study that as the height of the building increases, natural period is not linearly proportional to height; rather it is becoming flexible. Hence there is an urgent need for revision of the empirical expression.

@inproceedings{bib_STAT_2017, AUTHOR = {Sushma Pulikanti, Pradeep Kumar Ramancharla}, TITLE = {STATE OF STRESS OF A SFSI SYSTEM OF PILE SUPPORTED FRAME STRUCTURE-LINEAR AND NONLINEAR ANALYSIS}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

Experiences from past earthquake disasters clearly shows that the ground motion was responsible for majority of property and life loss. Among the collapsed structures during the 1964 Niigata earthquake, the 1995 Kobe earthquake, the 1999 Koceli earthquake, the 2001 Bhuj earthquake and the 2004 Sumatra earthquake, excessive damage was occurred to pile supported bridges, towers, chimneys, high rise structures, etc. In view of this, there is a need to study the complex behaviour of soil-pile-structure interaction problems. In this research paper, a numerical study is carried out to understand the dynamic soil Foundation structure interaction (SFSI) of a framed structure supported on a pile foundation. For that purpose a 5 storey pile supported framed structure is modeled and the behaviour under strong earthquake excitations associated with nonlinear material behaviour is studied. A peculiar behaviour in the stress state of pile in the SFSI system is observed. This behaviour is because of Soil resistance acting downward along the pile shaft because of an applied transient load. Also, the comparison of linear and nonlinear stress states and the effect/significance of soil plasticity on the stress states are commented.

@inproceedings{bib_Desi_2017, AUTHOR = {Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {Design Amplification Factor for Open Ground Storey RC Structure with Infill Openings in Upper Storeys}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

Reinforced concrete structures with open ground storey have shown very poor earthquake performance during past events. Despite of considering the design recommendations provided in the various international codes of practices for structural elements of open ground storey, the damage in the building has not reduced significantly. Literature shows damage to structural members in the soft storey depends on their relative stiffness with respect to adjacent storeys and eventually affects the deformation characteristics. Hence the problem of soft storey cannot be addressed independently without considering the relative effects of adjacent storeys. In this paper, the seismic response of open ground storey structure with openings in the upper storeys is studied and amplification factor for designing and strengthening of open ground storey members is determined. Static Nonlinear pushover analysis is used to carry out the study. The main parameters investigated are stiffness, strength, inter-storey drift and fundamental period. It is found that the presence of wall opening in upper storey will decrease its stiffness and strength significantly compared to full infill, which directly leads to reduction in the deformation and decrease in amplification factors for design and strengthening of ground storey members.

@inproceedings{bib_Para_2017, AUTHOR = {MEEGADA V RAVI KISHORE REDDY, Supriya Mohanty, , Pradeep Kumar Ramancharla}, TITLE = {Parametric Study on Behavior of Foundation Resting on Reinforced Pond Ash Deposit}, BOOKTITLE = {Indian Geotechnical Conference}. YEAR = {2017}}

This paper presents a parametric study on behavior of a shallow foundation resting on pond ash deposit with and without reinforcement. The behavior of foundation resting on the reinforced ash deposit is examined and studied by considering the parameters like effective depth of reinforcement; width of reinforcement; number of reinforcing layers. The parametric study has been performed using three dimensional finite element software, PLAXIS 3D. With the provision of reinforcement, the displacement is reduced as compared to unreinforced case. Also, with the increase in number of reinforcement layers, the bearing capacity of reinforced pond ash foundation is increased. Based on the results obtained, it is concluded that effective placement of reinforcement is observed at a depth of 2.67 B below the foundation for a width of 2B. Also, with the increase in number of layers, the bearing capacity is increased and the optimum provision of number of reinforcing layers is found to be two. Hence, it can be concluded that the performance of shallow foundation is better when pond ash underlying the shallow foundation is reinforced with geosynthetics material.

@inproceedings{bib_DEFI_2017, AUTHOR = {Aniket Bhalkikar, Pradeep Kumar Ramancharla}, TITLE = {DEFINING VULNERABILITY SCORE MODIFIERS FOR PARAMETERS THAT AFFECT RAPID VISUAL SURVEY SCORE: A NUMERICAL STUDY}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

It is well known that loss of life during an earthquake event is mainly due to collapse of buildings that are not designed, executed or maintained properly. Therefore there is an urge for pre-earthquake vulnerability assessment of buildings in moderate-to-severe earthquake prone areas world-wide. Vulnerability assessment of a building is a challenging task and it has to be dealt very carefully. However, for large number of buildings in a city or town, some simple methods have to be employed. Rapid Visual Survey (RVS) is one such method which is widely used all over the world. It uses many parameters like presence of soft storey, plan irregularities, stiffness irregularities, short-column effect, etc., for evaluating the score. This score has a limitation because the forms that are developed at one place cannot be used in different region, due to large variation in design guidelines and construction technology and hence it is important to develop forms which are specific to an area and also building technology used. In addition, it is also important to calibrate RVS scores to possible damage indicators. Hence it is important to know the effect of individual parameter (ie, vulnerability score modifier) on the overall score. This paper describes the numerical procedure for defining the value of vulnerability score modifiers for parameters that affect RVS score.

@inproceedings{bib_EFFE_2017, AUTHOR = {Archana Dongre, Pradeep Kumar Ramancharla}, TITLE = {EFFECT OF OPENINGS AND ASPECT RATIO ON OVERALL PERFORMANCE OF RC FRAMED BRICK INFILLED BUILDING}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2017}}

ndia and nearby countries in Asia witness major earthquake in recent days and in past. Although after witnessing many earthquakes in past, for aesthetic purpose big window openings in wall and even whole brick wall replaced by glass can be seen in metro cities and suburban areas in cities of India. Opening and aspect ratio in wall plays great role in strength and stiffness of wall and overall behavior of building. Without understanding effect of openings and aspect ratio on strength, stiffness and behavior of wall it can be dangerous to use such practices in construction of building. In this research study, effect of opening and aspect ratio on overall behavior of building has been studied. This numerical study has been done by considering a RC framed brick infill wall using Applied Element method. Applied element method is capable of showing crack initiation, crack propagation till total collapse of building. This research study will focus on importance of placement of opening and consideration of aspect ratio for RC infilled brick masonry building.

@inproceedings{bib_Rapi_2017, AUTHOR = {SREERAMA AJAY KUMAR, CHENNA RAJARAM, Shashank Mishra, Pradeep Kumar Ramancharla, Anoop Karnath}, TITLE = {Rapid visual screening of different housing typologies in Himachal Pradesh, India}, BOOKTITLE = {Natural Hazards Journal}. YEAR = {2017}}

Methods capable of assessing the vulnerability of houses for future earthquakes are of fundamental importance for the safety and development of an area. As the detailed assessment is limited to number of houses and cost, one of the appraising methods currently used for seismic vulnerability assessment is rapid visual screening (RVS). This methodology has led to determination of risk of an area subjected to an earthquake event. Many codes have limited rapid visual screening to housing typologies like reinforced concrete and Brick masonry structures. This paper delivers an approach on how to perform RVS for five varieties of buildings in Himachal Pradesh state. The RVS scores have been calculated for 9099 buildings and normal distribution curves are plotted for each typology of building to understand the distribution of buildings in Himachal Pradesh. Finally, a new modified format for performing rapid …

@inproceedings{bib_Vuln_2017, AUTHOR = {Rajaram Chenna, T. ASHWINI REDDY, K. RENUKA DEVI, Pradeep Kumar Ramancharla}, TITLE = {Vulnerability Assessment of Coastal Structure: A Case Study on Light Houses}, BOOKTITLE = {Journal of The Institution of Engineers (India): Series A}. YEAR = {2017}}

Lighthouses are the road signs of the ocean. They guide sailors through dangerous waters. Each lighthouse design is based on the land it is built on, its purpose, and the technology available. The Geometry of the lighthouses is round, square, octagonal, or conical in shape. These lighthouses need to be in operation 24 × 7 guiding the ships coming towards the coast. However, these lighthouses got affected during past earthquakes. The main objective of this work is to perform the nonlinear time history analysis of Navadra, Kachchigadh and Dwaraka point lighthouses subjected to eight ground motions. Since most of the Gujarat state is under Zone-III, IV and V, the analysis is carried out by normalizing them to respective zone factors as suggested by Bureau of Indian Standards IS 1893 (part-1): 2002. Using energy dissipation approach, damage is quantified at every displacement level. A fragility curve has …

@inproceedings{bib_Unde_2017, AUTHOR = {SAURABH AGRAHARI, Pradeep Kumar Ramancharla}, TITLE = {Understanding The Behavior of Flat Slab by Linear and Nonlinear Finite Element Analysis}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2017}}

In the present situation of building construction around the world, Flat slab is becoming widely popular in the multi-storied buildings due to its advantage and ease of construction over the slabs. However, during past earthquakes, many building with flats have performed poorly. This is mainly due to inadequate resistance for punching shear under the earthquake loading. Many codes that are available for the design are for the analysis of flat slab under gravity loading. Some provisions exist for punching shear resistance, however, they are inadequate. To understand the behavior of building with flat slab subjected lateral loads, a numerical study is performed. A three-dimensional finite element method is used to perform the analysis. A flat slab along with the columns is modelled. Nonlinear constitute equations are used to model material, ie, concrete. Parametric study is performed for understanding the nonlinear behavior of flat slab subjected to lateral loads.

@inproceedings{bib_Prop_2016, AUTHOR = {Pulkit Velani, Pradeep Kumar Ramancharla}, TITLE = {Proposed new empirical expression for natural period of RC tall buildings in India}, BOOKTITLE = {International Journal of Research in Engineering and Technology}. YEAR = {2016}}

Urbanization is rapidly increasing in almost every city in India. Huge infrastructure developmental plans have been laid by the government and private organizations. Large advertising boards of tall buildings (ranging from 30 to 50 floors) already started attracting people to invest in these infrastructure plans. However, from the point of view of seismic hazard prevailing in the country,“Will these buildings survive during future earthquakes?” is a question to be answered before proceeding for construction. In last 2.5 decades, 7 moderate earthquakes have been witnessed: Bihar-Nepal border (M6. 4) in 1988, Uttarkashi (M6. 6) in 1991, Killari (M6. 3) in 1993, Jabalpur (M6. 0) in 1997, Chamoli (M6. 8) in 1999, Bhuj (M6. 9) in 2001, A&N Islands (M9. 3) in 2004, Muzaffarabad (M7. 2) in 2005, Sikkim (M6. 8) in 2011 and more recently Twin Earthquakes in the neighborhood Nepal. These earthquakes have clearly exposed the lack of understanding of seismic hazard of the country. Sometimes, even when the hazard is understood, the lack of knowledge is exposed on earthquake resistant design and construction practice of reinforced concrete structures. The professionals involved in building construction should be more concerned with the safety of building infrastructure during future earthquake events. Among several aspects, natural period of building is one of the crucial parameters which decide the seismic demand of the building. Present study focuses on developing an empirical expression of fundamental natural period of RC tall buildings in India with the help of ambient vibration tests. Through the study it is found that the periodheight relationship is …

@inproceedings{bib_Comp_2016, AUTHOR = {Swajit Singh Goud, Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Comparative Study on Materials used in Various Codes for Design of RC and Steel Structures}, BOOKTITLE = {CONCRETE: DESIGN CODES}. YEAR = {2016}}

Indian standard code of practice for plain and reinforced concrete IS 456 was last revised in 2000 after 22 years of the third revision. The major revision done in the new code is shift in design philosophy from working stress method to limit state method. The new code has not shown any significant changes in the concepts of structural design, material properties for high strength of concrete and steel, material grade limitation for seismic design, design of deep beam and walls, design of infilled frames, design of beam column joint and provisions for effective length of frame members. The code does not clearly mention about mode of failures such as shear, flexure in structural members. In the present paper a comprehensive literature review on the design strength of materials, stress stain curve for concrete, steel and confined concrete, partial safety factors and limitations/recommendations for usage of concrete grade and reinforcement steel grade in design provisions of Indian Standards, American Standards, European Standards, New Zealand Standards, Japanese Standards and from the latest available literature is done.

@inproceedings{bib_Simu_2016, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Simulation of near-field ground motion characteristics of May 01, 2013, Doda earthquake using modified semi-empirical approach}, BOOKTITLE = {Natural Hazards Journal}. YEAR = {2016}}

Strong ground motions are the most desirable for the earthquake-resistant design of structures. If the site at which a major construction is required has less ground motion records, then artificial ground motions will serve the purpose. In highly seismic areas like Kashmir and the Himalaya region, artificial ground motions are quite helpful. Artificial accelerograms can be generated either through analytical or numerical procedures. Several methods were suggested in the literature for generating artificial ground motions. However, suitability of method for the region is to be understood before application. The main objective of this paper is to generate synthetic accelerograms of May 01, 2013, Doda earthquake using modified semi-empirical approach. A MATLAB code is written to generate the ground motion records of 1991 Uttarkashi earthquake and also validate the results. Based on effectiveness of the code …

@inproceedings{bib_Calc_2016, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Calculation of separation distance between adjacent buildings: a review on codal provisions}, BOOKTITLE = {Journal of Seismology and Earthquake Engineering}. YEAR = {2016}}

Structures are being built very close to each other in metropolitan areas where the cost of land is very high. Due to the proximity of the structures, they often collide with each other when subjected to earthquakes. To mitigate the amount of damage from pounding, the most simplest and effective way is to provide minimum separation distance. Generally most of the existing buildings in seismically moderate regions are built without codal provisions. The main objective of the present study is to check the adequacy of provisions given in codes of various countries. For this purpose, four pairs of structures were selected. The gap between structures was estimated according to codes of different countries and the same were subjected to earthquake excitation. Some codal provisions failed to satisfy the safety requirements, whereas some were safe. Based on this study, recommendations were drawn.

@inproceedings{bib_Web__2016, AUTHOR = {AYAN SRIVASTAVA, Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {Web Application For Analysis and Monitoring of Flat Thin Rectangular Glass Panel in Buildings Subjected to Wind and Seismic Forces}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2016}}

Huge damages and loss of lives due to failure of glass panels and façade structures in buildings reported during past disasters such as the 1983 Mid-Japan Sea Earthquake and glass curtain façade failures due to 1994 Typhoon in Wan Chai district of Hong Kong suggest that there is a significant difference between available research literature related to structural mechanics, codes available on glass failure behavior and that with the safe structural design, mitigation practices actually implemented by modern construction firms and industries using significant structural glass components in buildings especially in newly emerging cities of India. This study presents a web application that simulates the behavior of glass plates towards two independent loading events: wind pressure acting transversely on the plates and seismic excitations deforming the in-plane glass frames leading to stress concentration patterns around plates. The App starts by prompting the user to input site-specific, plate geometry, building type and class, terrain, location-specific parameters. The framework of the application is designed in three stages. Stage-I uses computational GPS algorithms to determine Basic wind speed of the location based on wind zone map of India, combines analytical procedures in IS 875 Part III and Indian draft codes to formulate SNT (Standard Nominal Thickness) of glass plates and net design wind pressure acting transversely on them. In stage II, Deflection and bending behavior are investigated and relevant computations are performed. Mesh-generation procedures and Finite Element Method are implemented and coded by authors to solve the …

@inproceedings{bib_Unde_2016, AUTHOR = {RAMYA G, Pradeep Kumar Ramancharla}, TITLE = {Understanding Secondary Damages due to Non-Structural Elements in High-rise Buildings}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2016}}

In the present scenario of building construction world-wide, there is a significant increase in the cost percentage of non-structural elements compared to overall building cost. However, in some cases during past earthquakes, where the main structure suffered minimal damage, it was noticed that there were severe problems in the functionality of building and also sometimes leading to injuries & life loss. It is observed that significant percentage of population is injured due to overturning of objects such as furniture. This problem is attributed mainly to the behavior of non-structural elements which are not designed taking into account their seismic performance. The aim of this study is to analyze the behavior of a rigid body ie a NSE, particularly the toppling behavior under the action of seismic forces. A linearized solution for the dynamic equation of motion of the rigid body is obtained. The results are obtained in the form of angle of rotation of body against time, providing limits of safety of the NSE against toppling under applied seismic loading. A transformer has been modelled to illustrate the same. Also a tool has been generated using python scripts to graphically simulate the behavior of nonstructural elements under earthquake loading, by placing NSEs in different floors. This tool helps us in identifying whether the NSE will slide, rock or topple when subjected to certain seismic loading and provides the limits of safety for the same.

@inproceedings{bib_EFFE_2015, AUTHOR = {Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {EFFECTS OF ASPECT RATIO ON NONLINEAR SEISMIC PERFORMANCE OF RC BUILDINGS}, BOOKTITLE = {International Journal of Research in Engineering and Technology}. YEAR = {2015}}

Many countries have their own building codes-of-practice for earthquake resistant design of structures. These codes provide conventional approach to earthquake resistant design of buildings with sufficient strength, stiffness and inelastic deformation capacity to withstand a given level of earthquake generated force. Under a given earthquake, the level of damage to a structure is greatly influenced by nonlinear capacity of its members. Even when the nonlinear capacities are same, the overall damage is critically influenced by the structure’s shape, size and geometry.This paper presents the research on the influence of aspect ratio on overall damage of the structure subjected to earthquake loading. In this paper a numerical study is carried out for 3 benchmark structures, with an aspect ratio (height to widthratio) of 3, 1 and 0.3, to define failure pattern in nonlinear state. Nonlinear static pushover analysis is performed to understand the capacity of structure and expended energy based damage assessment is used to estimate the damage. The results are compared in terms of damage, displacement and plastic hinge pattern

@inproceedings{bib_Seis_2015, AUTHOR = {Sreekanth Gandla Nanabala, Pradeep Kumar Ramancharla, Arunakanthi E}, TITLE = {Seismic Analysis of A Normal Building and Floating Column Building}, BOOKTITLE = {International Journal of Engineering Research and Technology}. YEAR = {2015}}

n present scenario buildings with floating columns are of typical feature in the modern multistorey construction practices in urban India. Such types of constructions are highly undesirable in building built in seismically active areas. This paper studies the analysis of a G+5 storey normal building and a G+5 storey floating column building for external lateral forces. The analysis is done by the use of SAP 2000. This paper also studies the variation of the both structures by applying the intensities of the past earthquakes i.e., applying the ground motions to the both structures, from that displacement time history values are compared. This study is to find whether the structure is safe or unsafe with floating column when built in seismically active areas and also to find floating column building is economical or uneconomical.

@inproceedings{bib_Near_2015, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Near-field Simulation of Ground Motions of 16 April 2013 Iran-Pakistan Border Earthquake Using Semi-Empirical Approach}, BOOKTITLE = {Journal of Seismology and Earthquake Engineering}. YEAR = {2015}}

The 7.8 M earthquake occurred in south east Iran on 16 April 2013 at 10: 44: 20 UTC. This earthquake was the most massive earthquake in last 50 years, with tremors felt across Pakistan, Oman and UAE. According to BHRC (Iranian Building and Housing Research Center) report, this event was recorded by 33 digital accelerographs in Iran Strong Ground Motion Network. The peak acceleration was recorded in Sabz Gazz seismic station. This study presents simulation of near-field ground motions of the 2013 Iran earthquake. For this purpose, five seismic stations are selected to simulate ground motions using semi-empirical approach. Hamzehloo and Mahood (2012) attenuation relationship for south east Iran is used to obtain acceleration waveformenvelope function. Acomparison is done on characteristics of observed and simulated ground motions. The simulated results are satisfactory at many of the seismic stations. It is concluded that higher frequencies (2-10 Hz) of simulated ground motions match with observed ground motions.

@inproceedings{bib_Slop_2015, AUTHOR = {SREERAMA AJAY KUMAR, Pradeep Kumar Ramancharla}, TITLE = {Slope Hazard Threat Map of Aizawl District, Mizoram}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2015}}

The term natural hazard implies a natural phenomenon which may cause direct damage, injury, or harm to those in its path (Selby, 1993). In India, natural disasters majorly relates to its climatic conditions. For example disasters like droughts, flash floods, cyclones, avalanches, landslides by rains etc are the cause of massive loss of life and property. On the other side earthquakes also causes a major threat to the nation, where seismically triggered landslides are one among the many types of hazards. This hazard has greatly increased because of the expansion of commercial and residential development in to earthquake-prone slope side locations. Most moderate and large earthquakes produce ground motions that can trip Landslides, which poses a double threat to those living in these risk areas. This study mainly focuses on the threat assessment of buildings located on slopes prevalent to earthquake hazard and to develop a Slope Hazard Zonation Map for an area of interest. Keywords: Natural hazards, Earthquake risk, Landslides, Threat map.

@inproceedings{bib_Expa_2015, AUTHOR = {Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {Expanded Energy Based Damage Assessment of RC Structures}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2015}}

Capture the mechanical behaviour of RC frame systems subjected to Lateral loading and estimating the damage state of structure are still changing tasks in civil engineering

@inproceedings{bib_VISC_2015, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {VISCO-ELASTIC FE MODELING OF CONVERGENT PLATE MARGINS FOR UNDERSTANDING DEFORMATION TOPOLOGY IN TWO DIMENSIONAL}, BOOKTITLE = {INTERNATIONAL JOURNAL OF CURRENT RESEARCH}. YEAR = {2015}}

Crustal deformation in vertical direction is higher at convergent plate marg other plate margins. Even though there are three types of convergent plate mar continental-continental plate, oceanic-continental plate and oceani considers only the interaction between oceanic plate and continental plate lithospheric mantle to understand the topography effect on continental plate. T element models are developed and analyzed using commercially availabl Contact properties are defined between plates so that effect of friction is calc an elasto-visco rheology and analysis is carried for 30000 years. The mo nclination angles leading to subduction or collision effects the length of vertic Also, increasing the coefficient of friction decreases the vertical deforma amount of subsidence. This study concludes inclination angle and coefficient role for the development of higher topographic regions at convergent plate mar asupuleti and Pradeep Kumar Ramancharla. This is an open access article distributed un use, distribution, and reproduction in any medium, provided the original work is properl evolved to be one of the most aining the behaviour of rigid the earth’s surface leading to Convergent, Divergent and dynamic evolution of the, 1965). One of the nteraction leading to different re found where tectonic plates te boundaries comprise both At subduction zones geological suggest that convergence is plate (oceanic plate) r oceanic plate). At collisional plates are both continental in the other carries a magmatic. In simple the continental ion) normally follows the convergent forces of lateral Turcotte and Schubert, bservations show that vertical surface near convergent …

@inproceedings{bib_Comp_2015, AUTHOR = {S BHARGAVI, Pradeep Kumar Ramancharla}, TITLE = {Comparison between the effect of lintel and lintel band on the global performance of load bearing walls and masonry infilled RC frames}, BOOKTITLE = {INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY}. YEAR = {2015}}

Improperly designed brick masonry walls cause undesirable effects under seismic loading in both brick masonry in-filled reinforced concrete (RC) frames and masonry load bearing wall structures. Doors and windows (openings) are unavoidable components in brick masonry in-filled RC structures and masonry load bearing wall structures because of its functional and ventilation requirements. The presence of openings in brick masonry walls reduces the lateral stiffness and strength of the wall in both RC and load bearing structures, which changes the actual behavior of structure. If these openings are located in the restricted zones like areas within middle two thirds of a wall wall, then the wall needs to be strengthened by providing necessary horizontal/vertical (bands) structural elements such as lintel or lintel bands around them. Lack of such structural elements may cause the structure to undergo severe damage during the earthquake event. In this paper, two case studies,(a) the presence of openings in infill wall with or without lintel and lintel band (b) the presence of openings in load bearing wall with or without lintel and lintel band is studied, to know the nonlinear response of brick masonry in-filled RC frame and load bearing wall under seismic loading. To understand the behaviour of the infilled frames and load bearing wall, a two dimensional (2D) infilled frame and load bearing wall is modeled and analyzed using a tool based on Applied Element Method (AEM). Nonlinear static pushover (SPO) is performed to estimate capacity of the models.

@inproceedings{bib_Gene_2015, AUTHOR = {A BHIJIT M OLAWADE, Rajaram Chenna, Pradeep Kumar Ramancharla, T. Vijay Kumar}, TITLE = {Generation of Site Specific Response Spectrum near Nuclear Power Plants: A Preliminary Case Study at Rawatbhata Station}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2015}}

Nuclear power plant is one of the largest source of producing electricity in India after thermal, hydroelectric and renewable sources of electricity. As of 2013, India has 21 nuclear reactors in operation in 6 nuclear power plants, having an installed capacity of 5780 MW and producing a total of 30, 293 GWh of electricity while six other reactors are under construction and are expected to generate an additional 6,100 MW. After 2011 Fukushima earthquake in Japan, safety of nuclear reactors has become a major concern. For assessing safety it is utmost important to have information on expected earthquake events. In case of lack of sufficient information, artificial ground motions may be generated by using geological features and faults information. This study presents simulation of near field generated ground motions of Rawatbhata nuclear power plant. For this purpose, three faults nearer to the power plant have been selected to the generate ground motions using semi-empirical approach. It is observed that as the source (M) of the earthquake increases, the amplitude of the ground motion, duration and energy content increases. Similarly, the spectral accelerations also increase due to all three active faults.

@inproceedings{bib_Hori_2015, AUTHOR = {Velani Pulkit Dilip, Pradeep Kumar Ramancharla}, TITLE = {Horizontal and Vertical Crustal Deformation profiles of a simple Convergent plate margin using Contact Analysis}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2015}}

The process of crustal deformation depends on the type of tectonic plate interactions viz. convergent, divergent and transform. For all the three cases, the topography effect is different. However, higher elevations and huge compressions are measured at convergent plate margins. Past observations reveal that these margins are very much prone to great earthquakes especially at the locations where oceanic plate is subducting underneath a continental plate. For the purpose of understanding horizontal and vertical displacement profiles on both the plates, a study considering the interaction between oceanic and continental plate which are resting on lithosphere mantle is carried out. Two dimensional finite element models were developed and analyzed using commercially available software ABAQUS. Contact properties are defined between plates so that effect of friction is calculated. All plates have an elastic rheology and slip is allowed at the interfaces. The models demonstrate that inclination angles leading to subduction or collision affects the length of vertical and horizontal displacements. Also, increasing the coefficient of friction decreases the vertical deformation but increases the amount of subsidence. This study concludes that the inclination angle and coefficient of friction plays a vital role for the development of varied crustal deformations at convergent plate margins.

@inproceedings{bib_Prog_2015, AUTHOR = {Harinadha B. Raparla, Pradeep Kumar Ramancharla}, TITLE = {Progressive collapse analysis of RC buildings subjected to seismic loads}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2015}}

Earthquake performance of Reinforced concrete bare frame has been well documented in the past. Also, damage patterns in reinforced concrete frames during the past earthquakes have been extensively studied. However, more recently, several destructive earthquakes, including the 1999 Athens (Greece) earthquake, the 1999 Ýzmit and Düzce earthquakes (Turkey), 1999 Chi Chi (Taiwan) earthquake, 2001 Bhuj (India) earthquake, and the 2003 Boumerdes (Algeria) earthquake, have given more insights to performance of RC frame constructions. In order to understand the complete behavior of RC frame, it is required to study the performance from no loading condition till the complete collapse. In this paper, a set of four bare frames designed as per Indian Standards are considered. All the frames are subjected to Northridge earthquake ground motion. Newly developed numerical model called Applied Element Method (AEM) is considered for analysis. Initially, the linear analysis is carried out and the results were compared with commercially available software. Later, progressive collapse analysis is performed. Collapse process of each bare frame is discussed in detail.

@inproceedings{bib_Effe_2015, AUTHOR = {Shivam Mishra, Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {Effect of Column Cross Section Ge- ometry on Response Modification Factors}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2015}}

Different shapes of column cross sections are possible for design of structures which ultimately affect the overall performance. Various cross section reinforced concrete columns like square, circular, plus, L, and T shaped with same cross sectional area and reinforcement are modelled. In order to make this study more practically applicable, three models each of multi storeyed structures of different number of storeys were analysed for non-linear static responses. One of the models used conventional rectangular columns, second used circular columns throughout and another model employed combination of various geometrically possible column cross sections such as L, T and plus (+) shaped columns. The study compares response modification factors for above mentioned structures.

@inproceedings{bib_Rati_2015, AUTHOR = {Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {Rationalizing acceptable levels of damage for structures designed as per codes IS 456, IS 1893 and IS 13920}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2015}}

Past earthquakes in India have caused maior damage to structures even for lesser peak ground acceleration than it is designed for. This is because of lack of incorporation of earthquake resistant design features in the structure. In India most of the structures are designed for gravity loads only. It is due to lack of knowledge and awareness of earthquake resistant design and the myth that earthquake resistant design is costlier. in this view, present study aims at comparing normal detailing as per IS 456: 2000 and ductile detailing as per IS 13920 (Proposed draft) in terms of its capacity, damage and cost. A parametric study has been carried out by considering a 5 storey building, designed for gravity loads as well as, lateral load as per IS 18931002, for different seismic zones (Zone II to V) and results are compared. Static Non Linear (Pushover) analysis and fragility analysis are performed for estimation of post damage …

@inproceedings{bib_Calc_2014, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Calculating Euler Pole of Indian Seisotectonic Plate with Respective to its Neighboring Plates}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2014}}

Magnitudes that have the epicentrical distance from7 to 343 kilometers. The focal depth ranges from 20-100 km. The seimograms which are used in this study.

@inproceedings{bib_Nume_2014, AUTHOR = {Ahmed Hussain, Pradeep Kumar Ramancharla}, TITLE = {Numerical Study of Spatial Variation of Ground Motion by Modeling Dip-Slip Surface Faults}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2014}}

Saturation area E and porisity paramenter using new data set recorded by the Gujarath sesmic network of India.

@inproceedings{bib_Stud_2014, AUTHOR = {Vasudeo Chaudhary, Pradeep Kumar Ramancharla}, TITLE = {Study of Pipeline Subjected to Permanent Ground Deformation Numerical Study of Spatial Variation of Ground Motion by Modeling Dip-Slip Surface Faults}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2014}}

day by day increasing cost of vehicle transport service for petrolium product, made pipeline as more affordable mean

@inproceedings{bib_Vuln_2014, AUTHOR = {Rajaram Chenna, Ajay Pratap Singh, Pradeep Kumar Ramancharla, Bal Krishna Rastogi}, TITLE = {Vulnerability Assessment of Kandla Port Building}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2014}}

Ports are lifeline systems that function as storage and maintaning facility for the transport of cargos. The port structures are frequently exposed to failure under

@inproceedings{bib_Gene_2014, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Generation of Synthetic Accelerogram of 16th April 2013, Iran-Pakistan Border Earthquake Using Semi Empirical Approach}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2014}}

Symatically analyzied b- value variation in space as well as in time

@inproceedings{bib_Vuln_2014, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Vulnerability Assessment of Coastal Structure: A Study on Port Buildings}, BOOKTITLE = {International Journal of Education and Applied Research}. YEAR = {2014}}

Ports are lifeline systems that function as storage and maintenance facilities for the transport of cargos. The port structures are frequently exposed to failure under severe seismic loading, for example, 1995 Kobe, 1989 Loma prieta, 1999 Kocaeli and 2001 Bhuj earthquakes. The scenario is more critical if the port sites are located within the seismically vulnerable area like Gujarat state of India. This clearly indicates the importance of port buildings and stability that can withstand natural disasters particularly earthquakes. The main objective of this paper is to perform the nonlinear dynamic analysis of Kandla port building subjected to ground motion. Ground motions generated by Institute of Seismological Research (ISR), Gujarat at four locations on Katrol Hill Fault (KHF) and Kachchh Mainland Fault (KMF) were used in the analysis. Finally, the damage of the Kandla port building is estimated though fragility curves. The damage values obtained from fragility curve are 0.46, 0.17 and 0.88 for KHF Mandvi, NKF Jodiya and KMF Jhangi ground motions respectively.

@inproceedings{bib_Seis_2014, AUTHOR = {PATNALA V S NEELIMA, Pradeep Kumar Ramancharla}, TITLE = {Seismic Behaviour of RC Frame with URM Infill: A Case Study}, BOOKTITLE = {International Journal of Education and Applied Research}. YEAR = {2014}}

Masonry is one of the most common types of construction materials in India. It is commonly used for infill walls in Ordinary Moment Resisting Frames. The strength based design in the code considers the masonry wall as non-structural element and its load is considered on the corresponding elements. The numerical modeling of infill is completely disregarded during analysis of the structure. To design a building realistically, the behaviour of all the primary components is needed and the load carrying capacities are required to be properly assessed. Apart from the strength based design adopted in the code of practice, the modern and advanced approach to design, the performance based design, needs a proper understanding of the behaviour of all the structural elements. Analytical modeling of infill is attempted by many researchers using equivalent strut and tie models which can idealize the behaviour of masonry infill to some extent. The effect of masonry wall on RC frame can be well understood by continuum modeling. Numerical modeling of masonry infill wall is done using Finite Element Method. This paper attempts to simulate the nonlinear behaviour of URM infill frames with varying storeys using Applied Element Method (ARM). Two bay ordinary moment resisting frame is considered with and without infill and capacity is obtained using Nonlinear Static Pushover analysis. One, two and three storey frames with and without openings are also analyzed to understand the differences in drift ratios and the strength of the frame. It is observed that the bare frame carries lesser drift when compared to the frame with infill. This clearly proves the increase in ductility of the frame when provided with infill. In the analyses of infill frame without door and window openings, the maximum base shear of the frame decreased and the drift carrying capacity increased with the increase in number of storeys. Almost the similar behaviour is observed when the infill frame with openings is analyzed.

@inproceedings{bib_SIGN_2014, AUTHOR = {RAVIKANTH CH, Pradeep Kumar Ramancharla}, TITLE = {SIGNIFICANCE OF SHEAR WALL IN HIGHRISE IRREGULAR BUILDINGS}, BOOKTITLE = {International Journal of Education and Applied Research}. YEAR = {2014}}

The usefulness of shear walls in the structural planning of multi-story buildings has long been recognized. When walls are situated in advantageous positions in a building, they can be very efficient in resisting lateral loads originating from wind or earthquakes. Reinforced concrete framed buildings are adequate for resisting both vertical and horizontal loads acting on them. Extensive research has been done in the design and analysis of shear wall highrise buildings. However, significance of shear wall in highrise irregular structures is not much discussed in literature. A study on an irregular highrise building with shear wall and without shear wall was studied to understand the lateral loads, story drifts and torsion effects. From the results it is inferred that shear walls are more resistant to lateral loads in an irregular structure.

@inproceedings{bib_Appl_2014, AUTHOR = {K. JAGAN MOHAN, Pradeep Kumar Ramancharla}, TITLE = {Applied Element Method to understand Seismic phenomenon: An example from Koyna Earthquake (1967)}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2014}}

Modern research in India on dams has entered a distinct phase subsequent to the damage to Koyna dam, located in hitherto considered stable continental part, due to an earthquake on 11th December, 1967 in Koyna district, India. Out of about 5,100 large dams in India, a significant number are in moderately high and high seismic zones. As such they may be prone to probable instability to the dam’s structure due to earthquake resultant impacts. Even though none of the dams other than Koyna got damaged in India due to high magnitude earthquake activity, since 1967, it is felt necessary to understand the behaviour of dams due to water load coupled with dynamics of faults that are present in the vicinity of the dam, as dam failures due to earthquake activity are reported from different parts of the world. In this paper, damage to Koyna dam due to a fault motion caused nearby has been studied. A concrete gravity dam is selected from the National Importance Dams of India. Structure-1(S1) as a concrete gravity dam with foundation and structure-2 (S2) as a concrete gravity dam with foundation and soil strata are numerically modeled using Applied Element Method (AEM). Displacement at the base of soil strata is given to generate reverse fault effect on the dam. Behavior of dam is studied by direct and sub-structure methods. In the direct method, the effect of fault motion on dam is studied in S2, by modeling dam at different locations on foot wall and hanging wall. In sub-structure method, free-field accelerations are recorded at different locations on foot wall and hanging wall while only the sub-structure is subjected to fault motion. The recorded accelerations on the surface are used as input to analyze super structure S1. Comparison on behavior of dam in models S1 and S2 is later drawn.

@inproceedings{bib_Effe_2014, AUTHOR = {Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {Effect of a Member on Global Performance of a Structure A Case Study on 5 Storey RC Frame}, BOOKTITLE = {Advances in Civil Engineering and Infrastructure Development}. YEAR = {2014}}

The overall capacity of a structure depends on the strength and deformation capacity of the individual components of the structure. This paper deals with the prediction of effect of a member on global performance of the structure. The performance of a 5 storey RC frame, designed for Indian standard codes has been presented. Non linear pushover analysis is used to draw the capacity curve. During the pushover analysis when the structure becomes unstable, the failed members are identified. In the present study, end columns of the bottom storey which exists in failed members are strengthened by increasing the longitudinal reinforcement, increasing the c/s area and reducing the shear reinforcement spacing. Increase of longitudinal reinforcement or decrease of shear reinforcement spacing not effected much the strength capacity, but the ductility is increased in both the cases. Increasing the c/s area of two columns increased the strength and stiffness of the frame, but the ductility is increased up to a certain limit and then decreased. Parametric study also done for individual column performance with same geometric and material properties as it exists in the frame. The performance of individual column is completely different with frame performance though the geometric and material properties are same this is because of the frame action where redistribution of forces takes place when the member fails in the frame.

@inproceedings{bib_Comp_2014, AUTHOR = {Pulkit Velani, Pradeep Kumar Ramancharla}, TITLE = {Comparing the empirical time period formula given in seismic code of different countries with Indian seismic code IS 1893:2002}, BOOKTITLE = {Advances in Civil Engineering and Infrastructure Development}. YEAR = {2014}}

Tall building construction is booming in India. There are several earthquake safety issues involved in planning, designing and constructing these buildings. Some issues related to seismic behaviour are still not resolved even in developed countries, like USA and Japan. Researchers all over the world are continuously working towards development of latest techniques for improving earthquake safety of tall building. The situation in India is that there are few codes which specify guidelines for earthquake resistant design of structures. However, the guidelines given in this code are useful for regular and relatively small, low-rise buildings. When it comes to tall buildings, every structure is special, several parameter needed to be considered. One such parameter is T. Existing empirical natural period equation given in IS 1893 is suitable only for small to medium rise buildings. There is a serious need for proposing equation for high rise buildings. In this paper an attempt is made to compare empirical equations for natural period of different countries. Study gives that there is a need to propose the new time period formula exclusively for Tall structure based on Indian condition.

@inproceedings{bib_Seis_2014, AUTHOR = {S BHARGAVI, Pradeep Kumar Ramancharla}, TITLE = {Seismic behaviour of fixed and flexible 2d RC frame: A case Study}, BOOKTITLE = {Advances in Civil Engineering and Infrastructure Development}. YEAR = {2014}}

Response of a structure subjected to gravity and lateral loads depends on the boundary conditions assigned at the base of structure in numerical modeling. Most of the structures are analyzed considering fixed base, but in reality, foundation is not fixed. The fixity depends on the interaction between the soil and foundation. In most of the cases base of a structure undergoes small amount of rotation because of flexibility induced by soil especially at the time of earthquake. Difference in boundary conditions used in analysis and in actual conditions will lead to improper estimation of the design forces, to reduce such effects in numerical analysis fixed base of structure can be replaced by springs or structure base resting on soil to obtain results closer to that of actual base conditions. Stiffness of the spring depends on geotechnical parameters as well as on the dimensions of the foundation. In the present paper an attempt is made to understand the difference between the Linear and Non Linear response of a frame having fixed base, spring base and with soil. Stiffness of springs for spring base structure is calculated as per ATC-40 [1] and JICA [7]. Analysis of structure with soil modeling is complex, specifically for Non Linear behavior for this Applied Element Method is used. Linear and Non Linear response is compared in terms of stress resultants and capacity of the frame respectively, for non linear response static pushover analysis is done. From the study, it is observed that the actual capacity of structure is overestimated assuming fixed base. The fact that the initial stiffness of the structure is governed by the soil stiffness can be clearly stated from the obtained pushover curves. It is also recommended that analysis of structure should be done considering spring base in place of fixed support.

@inproceedings{bib_Dama_2014, AUTHOR = {Vrushal Kamalakar, Pradeep Kumar Ramancharla}, TITLE = {Damage Based Life of Heritage Structures in Seismic Environment: A Case Study on Golkonda Fort}, BOOKTITLE = {Advances in Civil Engineering and Infrastructure Development}. YEAR = {2014}}

The earthquake resistant design of structures according to the existing design philosophy aims to ensure that during their lifetime, the structures resist the maximum possible earthquake without collapse. This philosophy ignores the fact that for the allowable damage at the end of the design life, it is necessary to account for the seismicity of the area in a comprehensive manner i.e., in terms of magnitudes with proper spatial distributions around the site. It is also necessary to estimate damage due to each of these events and also cumulative damage till date. Such a procedure is proposed in the paper and it is applied to heritage structures which stand for longer duration compared to ordinary buildings. As a case study, the proposed methodology is used to evaluate damage to Golkonda Fort located in Zone II according to IS 1893-2002. Proposed approach is based on the estimation of Power spectral density function (PSDF) of earthquakes already occurred and then estimation of damage to the structure during each of these events. Golkonda Fort is modeled using Applied Element Method (AEM). Pushover analysis of the AEM model is also carried out. The damage computed from the proposed approach is plotted on the fragility curve obtained from the push over analysis for comparison.

@inproceedings{bib_SSI__2014, AUTHOR = {SUSHMA P, Pradeep Kumar Ramancharla}, TITLE = {SSI Analysis of Framed Structure Supported on Pile Foundations - With and Without Interface Elements}, BOOKTITLE = {Frontiers in Geotechnical Engineering}. YEAR = {2014}}

In this paper an attempt has been made to understand the Soil Structure Interaction behavior of pile supported framed buildings under transient loading by taking the interface effects between the pile and soil. For this purpose a three dimensional Finite Element Method is used for modelling the soil-pile structure interaction using SAP 2000. A single bay five storey framed structure with a pile group foundation is modelled. First the significance of soil foundation structure interaction over fixed base analysis is studied, it has been observed that the presence of soil and foundation make a considerable change in response with a shift of natural period of the system. Next, a parametric study has been done to understand the significance of interface behaviour on soil foundation structure interaction. From the results it has been observed that under transient loading the acceleration response of top floor is reduced by two times, when contact between pile and soil has been modeled.

@inproceedings{bib_Comp_2014, AUTHOR = {G. Sai Kiran, Kailash Rao, Pradeep Kumar Ramancharla}, TITLE = {Comparison of Design Procedures for Pre Engineering Buildings (PEB): A Case Study}, BOOKTITLE = {International Journal of Civil, Architectural, Structural and Construction Engineering}. YEAR = {2014}}

In recent years, the introduction of Pre Engineered Building (PEB) concept in the design of structures has helped in optimizing design. The adoptability of PEB in the p lace of Conventional Steel Building (CSB) design concept re sulted in many advantages, including economy and easier fabricatio n. In this study, an industrial structure (Ware House) is analyzed an d designed according to the Indian standards, IS 800&1984, IS 800&2007 and also by referring MBMA&96 and AISC&89. In this study, a structure with length 187m,width 40m,with clear height 8m and havi ng R&Slope 1:10,isconsidered to carry out analysis& design for 2D frames (End frame, frame without crane and frame with 3 module cranes). The economy of the structure is discussed in terms of i ts weight comparison, between Indian codes (IS800&1984, IS800 &2007) & American code (MBMA&96), & between Indian codes (IS 800&1984, IS800&2007).

@inproceedings{bib_2D_N_2014, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {2D Numerical Modelling for Understanding Crustal Deformations at Convergent Plate Margins}, BOOKTITLE = {International Research Journal of Earth Sciences}. YEAR = {2014}}

Continental subduction and collision normally follows oceanic subduction leading to enormous crustal deformations. For understanding this mechanism oftectonic plates in collision area, which may propagate into the subductioncollision transition zone is of great interest. At the locations of high-pressure metamorphism, some places form huge crustal deformations like between Indian-Eurasian plates, and subduction at other places like Indian-Burmese plates. In either of the casesdeformation is a continuous, dynamic process. To understand the process, a study has been carried out using two dimensional finite element modeling. With the current availability of computing technology, advanced numerical techniques and material models it would be an easy task to know the parameters effecting the transition from collision to subduction process between different tectonic plates. In this paper, simpleinclined models are used to study subduction-collision transition zone. Elastic material rheology is considered for all the tectonic plates and contact analysis is used for the tectonic plate interfaces for the implementation of weak zones. Parameters consideredfor this study are geometry of plates, friction at the interface and length of the plates. This study concludes that vertical surface displacements are largely effected by the considered parameters.

@inproceedings{bib_Vuln_2014, AUTHOR = {Rajaram Chenna, SRIKANTH T, Ajay Pratap Singh, Bal Krishna Rastogi, Pradeep Kumar Ramancharla}, TITLE = {Vulnerability Assessment of Buried Pipelines: A Case Study}, BOOKTITLE = {Frontiers in Geotechnical Engineering}. YEAR = {2014}}

The pipeline systems are commonly used to transport water, sewage, oil, natural gas and other materials world over. These pipelines run over long distances and in some instances they cross high seismic areas including fault crossings. Many buried pipelines in India run through high seismic areas and are exposed to considerable seismic risk. These pipelines should be designed in such a way that they remain functional even when they are subjected to high intensity earthquake shaking. This paper illustrates the performance of one of the high pressure gas pipeline in the state of Gujarat, under the fault movement. Analysis shows that the burial depth of pipeline should be minimized in the fault zones in order to reduce soil restrain on the pipeline during fault movement.

@inproceedings{bib_Thre_2014, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Three dimensional analysis of pounding between adjacent buildings}, BOOKTITLE = {Journal of Structural Engineering}. YEAR = {2014}}

D uring past earthquakes many buildings suffered severe structural damage. Besides damage due to inadequate design and execution, buildings and building components suffered damage due to pounding also. Pounding is defined as collision between two buildings or different parts of the same building leading to severe damage or even sometimes complete collapse. In addition to simple lateral collision, buildings may also collide in torsion mode arising due to eccentricity of mass and stiffness, causing severe damage to adjacent building. In this paper two single storey reinforced concrete buildings are considered. To study the torsional effects due to pounding, buildings with different setbacks and unequal storey levels are analyzed using SAP 2000. The effect of collision is more when structures are kept at extreme levels of setback. At different elevation levels, the pounding response changes significantly than the structures at same elevation levels. More collision force is generated at mid height of column level than other height levels because of shear amplification.

@inproceedings{bib_Fini_2014, AUTHOR = {Vasudeo Chaudhari, VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Finite Element Analysis of Buried Continuous Pipeline Subjected to Large Ground Motion}, BOOKTITLE = {Journal of Earthquake Science}. YEAR = {2014}}

Pipeline generally extends over long distances traversing through wide variety of different soils, geological conditions and regions with different seismicity and ground motions. Vulnerability of the pipeline due to seismic hazards can be divided in to three categories i.e. hazard due to ground vibration, hazard due to faulting and hazard due to permanent ground deformation (PGD). Though there are no severe damage were observed due ground vibration in the modern buried pipeline though it may trigger to secondary effect of landsliding and ground motion due to liquefaction. Main stream researches in past especially analytical models are limited to strike slip fault motions with tension in pipe case only. As the large geometric changes incorporating in analytical study is a tricky task; however pipeline subjected to the large ground motion itself is a phenomenon of large geometric changes. Especially when pipeline subjected to compression, where in addition to material deformation it also undergoes general as well as local buckling with bending, contradictorily past work mostly assumed that pipeline is under tension. With day by day increasing capacity of computation and advancement in numerical modelling, one can find more facts for pipeline subjected to large motions including cases of pipe under compression as well. In this paper, past work is reviewed for pipeline subjected to large ground motion. A three dimensional FE based numerical model is suggested to carry out pipeline performance of buried pipeline subjected to large motion. A proposed model includes material nonlinearity, as well as considers the large geometric deformation. For this purpose, three dimensional FE program is developed using MATLAB. Displacement controlled Arc-length technique is implemented to solve the nonlinear behavior. To reduce the computation time of analysis here parallelization tool kit of MATLAB is utilized. Keywords: Buried continuous pipeline; Large ground motion; Nonlinear-large deformation FEM; Displacement controlled Arc-length technique.

@inproceedings{bib_Inte_2014, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Interactions and Seismicity of Indian Tectonic Plate with its Neighboring Plates: An Overview}, BOOKTITLE = {International Journal of Advanced Earth Science and Engineering}. YEAR = {2014}}

Understanding earthquakes and its prediction is most challenging tasks. Even though the earthquakes have been understood clearly, the prediction of earthquakes would take more time to come into reality. For this, collection of earthquake data and its interpretation plays a vital role. Its importance continues for few more decades in understanding the various aspects of earth structure and tectonic plate interactions. India, the second largest populous country of the world has experienced and is continuing to experience both inter and intra plate earthquakes, claiming life loss as well as damage to built environment. Apart from earthquakes, India has also experienced Tsunamis in both the directions; eastern tsunamis from Sumatra and western tsunamis from Makran. In this paper using past earthquake data, Indian plate interactions with its neighboring major (Eurasia, Africa & Australia) and minor plates (Arabia, Burmese & Sunda plate) have been understood. Upon clearly observing seven interactions, it is clear that interaction types, their lengths and thickness of plate play a great role in the occurrence of major to great earthquakes.

@inproceedings{bib_SEIS_2014, AUTHOR = {Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {SEISMIC DESIGN PROVISIONS FOR DUCTILE DETAILED REINFORCED CONCRETE STRUCTURES}, BOOKTITLE = {Symposium on Earthquake Engineering}. YEAR = {2014}}

Most seismic design codes allow structure to be designed for lesser force than elastic force, thus allowing structure to damage at appropriate locations. Indian seismic code IS 1893-2002 divides seismic design of structures into three categories; Ordinary moment resisting frame, Intermediate moment resisting frame and Special moment resisting frame. The classification differs based on reinforcement detailing and response reduction factor. It is expected that the performance of ductile detailed building would be better than non ductile detailed building and the capacity shall be more and damage is less compared to non ductile detailed building. This paper compares the performance of structure designed considering non ductile detailing and ductile detailing, in terms of capacity, damage, response reduction factor and drift. As a case study, a 5 storey building designed for Gravity loads as well as lateral load as per IS: 1893-2002 for seismic zone III is considered. Static Non Linear (Pushover) analysis and fragility analysis are performed for estimation of post damage yielding behavior of structure. The change in non linear behaviour of structure based on assumed load patterns in pushover analysis is done. This paper also provides other important conclusions on seismic design provisions, response reduction factor and interstorey drift.

@inproceedings{bib_Simu_2014, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Simulation of Ground Motion Characteristics of the 20 September 1999 Chi-Chi Earthquake Using Semi-Empirical Approach}, BOOKTITLE = {Symposium on Earthquake Engineering}. YEAR = {2014}}

The Chi-Chi earthquake (M7.6) was triggered on 20th September 1999 at 17:47:12 UTC in Chi-Chi, Taiwan. This was the largest inland earthquake occurred in Taiwan region. Chelungpu fault was the main cause for this earthquake and the fault was ruptured over 100 km. The ground motions were recorded at more than 600 stations. This study presents simulation of near field ground motions of 1999 Chi-Chi earthquake. For this purpose, 3 stations on foot wall side and 7 stations on hanging wall side are selected to generate ground motions using semi-empirical approach. The ground motion characteristics of the earthquake are calculated at 10 stations. It is found that the distribution of peak ground acceleration (PGA) obtained from semi-empirical approach, similar to real PGA distribution. Higher frequencies of simulated ground motions match with frequencies of real ground motions.

@inproceedings{bib_NON-_2014, AUTHOR = {K. JAGAN MOHAN, Pradeep Kumar Ramancharla}, TITLE = {NON-LINEAR RESPONSE OF A CONCRETE GRAVITY DAM SUBJECTED TO NEAR-FIELD GROUND MOTIONS}, BOOKTITLE = {Symposium on Earthquake Engineering}. YEAR = {2014}}

Lifeline structures like dams should always be designed for highest safety, resisting worst forces of nature. However, events that took place across the world proved how devastating an earthquake could be, particularly in the near-field areas. Landers earthquake (1992 – Mw 7.3), Northridge earthquake (1994 – Mw 6.7), Hyogoken-Nanbu earthquake (1994 – Mw 6.8) and few more earthquake events caused damage due to near-field effects. Notable damage to Koyna dam due to Koyna earthquake (1967 – Mw 6.5), India and Shih-Kang DamdueChi-Chi earthquake (1999 – MW 7.6), Taiwan proved earthquakes and near-field effects can cause damage even to dams. In India there are several dams constructed near the active faults, which might suffer moderate to severe damage in an event of earthquake in near-field areas. In this concern, a proper study on behaviour of concrete gravity dam subjected to near-field ground motions should be performed. In the proposed study, a concrete gravity dam is selected from the National Importance Dams of India (NRLD-2009) and numerically modeled using Applied Element Method (AEM). Fault normal and fault parallel components of 5 near-field ground motion are considered as input. The behaviour of dam subjected to near-field ground motions is then studied by understanding the displacement response, and stress distribution on upstream and downstream side of the dam body.

@inproceedings{bib_Para_2014, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Parametric Study to Understand the Transition from Collision to Subduction using 2D Finite Element Modeling}, BOOKTITLE = {Symposium on Earthquake Engineering}. YEAR = {2014}}

Understanding the mechanism behind the tectonic plates in collision area, which may propagate into the subduction-collision transition zone is of great interest. At the locations of high-pressure metamorphism, some places form huge crustal deformations like between Indian-Eurasian plates, and subduction at other places like Indian-Burmese plates. In either of the cases deformation is a continuous, dynamic process. To understand the process, a study has been carried out using two dimensional finite element modeling. With the availability of computing technology (Parallelization), advanced numerical models (FEM, XFEM) and material models (Elastic, Visco-elastic), it would be an easy task to know the parameters effecting the transition from collision to subduction process between different tectonic plates. In this paper, Arc-collision model is used to study subduction-collision transition zone. Visco-elastic material rheology is considered for all the tectonic plates. Effect of parameters such as geometry of plates, friction at the interface, length of the plates and type of loading are studied.

@inproceedings{bib_Rati_2014, AUTHOR = {Swajit Singh Goud, Pradeep Kumar Ramancharla}, TITLE = {Rationalizing Response Reduction Factor R for better Performance of Reinforced Concrete Framed Buildings}, BOOKTITLE = {National Conference on RECENT RESEARCH ADVANCES IN CIVIL ENGINEERING}. YEAR = {2014}}

Seismic resistant design philosophy incorporates the non linear response of the structure by using appropriate Response reduction factor (R). The value of R is directly related to the ductility level provided in the structure. Greater the assumed value of R, grater will be the ductility in the structure. The non linear response of structure will be more than the linear response because of material non linearity, factor of safety in load combinations, structural redundancy and ductility. Use of higher values of R is encouraged because of significant reduction in base shear leading to more economic structure. Value of R for reinforced concrete structure depends on the type of framing system. Proposed IS 1893 draft classifies framing into three categories i.e. 1) Ordinary Moment Resisting Frame (OMRF), 2) Intermediate Moment Resisting Frame (IMRF), and 3) Special Moment Resisting Frame (SMRF). In the paper, study is done to compute the value of R, component wise of a G+4 storey building designed for all seismic zones, considering ductile and non ductile design provisions and the same is compared with the assumed R to check the safety of the structures. R provided is computed from the obtained pushover curves.

@inproceedings{bib_Expe_2014, AUTHOR = {Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {Expended energy based damage assessment of RC bare frame using nonlinear pushover analysis}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2014}}

Past response analyses of structures under earthquake excitations revealed that both the maximum displacement and the number of inelastic excursions cause higher damage to the structure. However, it is observed that the quantification of damage is a difficult task. In the paper, a new methodology is proposed for the quantification of damage of reinforced concrete framed structure. This method is based on the nonlinear energy dissipated by the structure along the complete displacement path. Three methods have been proposed to assess the global damage state of the structure, for any deformation level. In these proposed methods, the damage index is expressed as the ratio of nonlinear dissipated energy at an instant, to the total non-linear energy capacity of the structure. To calculate the energy, pushover curve is plotted between base shear versus displacement at C.G of external force profile, which provides consistent meaning for work done by external forces. The area under the curve represents the energy dissipated by the structure. To illustrate the proposed concept, two cases i.e., G+5 and G+9 story structures have been considered. Keywords: Pushover analysis, expended energy, total energy, damage index.

@inproceedings{bib_Stre_2014, AUTHOR = {Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {Strengthening and repairing of 5-Storey RC ductile detailed structure with open ground storey}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2014}}

Reconnaissance reports of past earthquakes states that the open ground storey is one the most common problems, causing severe damage in the structural members of ground storey. In majority of the buildings, it was observed that even after proper ductile detailing, there is severe damage to the structure. This is mainly attributed to the presence soft storey. In this paper, a study is carried out to improve the seismic performance of a 5 storey open ground floor building with ductile detailing. The seismic performance is improved by: (a) providing wall infill in some portion, (b) increasing the moment carrying capacity of ground storey columns, and (c) combinations of the above two. The proposed methods can be used for new structures by incorporating the effect in design philosophy or can be implemented in the strengthening of existing structures. The performance of the structure is determined with the help of Non Linear Pushover analysis. The main parameters investigated are interstorey drift and lateral displacement. The study shows, with increase in design moments as per seismic codes for the columns having open ground storey will not improve the performance of the structure significantly. Also the open ground storey columns are severely damaged making their repairing difficult and costly. It is suggested that seismic performance of the structure can be improved more significantly by combination of constructing wall infill and higher design moments in columns; if damage occurs in wall only, it can be reconstructed and structure can be repaired easily. Keywords: Open ground storey, pushover analysis, retrofitting, design provision

@inproceedings{bib_Effe_2014, AUTHOR = {Neelima Patnala, Pradeep Kumar Ramancharla}, TITLE = {Effect of soft storey in a structure present in higher seismic zone areas}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2014}}

The use of unreinforced brick masonry as infill material in reinforced concrete frames is inevitable even in higher seismic zone areas. With increasing demands for architectural features in buildings, the provision of soft storey is a common practice in many multi storeyed structures throughout the world, for parking. The standard code of practice in many countries suggests higher design forces for the columns present in the soft storey. In order to understand the affect of increase in design seismic forces on the columns in a structure present in higher seismic zone areas, a study is carried out by taking pushover analysis as a tool for obtaining capacity of the structure. A comparative study between three types of arrangements; type I: structure with infill walls in all floors, type II: structure with open ground storey, type III: structure with open ground storey and columns designed for increased forces. It is observed that there is an increase in maximum load carrying capacity for the type III structure as compared to type II structure with no considerable change in behaviour of the two types of structures. It can be concluded that the increase in design forces of the columns at open ground storey may not lead to the safety as of structure type I. Keywords: Unreinforced brick masonry (URM), multi storeyed structures, higher seismic zone areas, soft storey, pushover analysis

@inproceedings{bib_Eart_2014, AUTHOR = {Pradeep Kumar Ramancharla, CVR Murty}, TITLE = {Earthquake safety of houses in India : Understanding the bottlenecks in implementation}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2014}}

According to current seismic zone map around 60% of India’s land area is prone to moderate to severe earthquakes. And earthquake losses, in terms of life and property in last 2 decades have been high, with housing contributing to over 95% of life loss; this failure attributed to improper design and construction practices of housing.Thus, all the three factors influencing earthquake risk of houses in India are above danger levels in many districts of India – hazard, exposure and vulnerability. This paper classifies housing risk in the entire country into four groups; about 47% of population is living in the highest risk. Gigantic effort is required to mitigate the risk. The paper also suggests some steps to move forward to reduce earthquake risk to housing in India.

@inproceedings{bib_Effe_2014, AUTHOR = {S BHARGAVI, Pradeep Kumar Ramancharla}, TITLE = {Effect of Lintel and Lintel Band on the Global Performance of Reinforced Concrete Masonry In-filled Frames}, BOOKTITLE = {International Journal of Research in Engineering and Technology}. YEAR = {2014}}

Door and window openings are unavoidable components in RC masonry in-filled frames because of functional and ventilation requirements. The presence of openings in RC masonry in- filled frames reduces the lateral stiffness and strength of the wall, which modifies the actual behavior of structure. If these openings are located in the restricted zones like areas within middle two thirds of a wall panel, then the wall needs to be strengthened by providing necessary structural elements such as lintel or lintel bands (i.e., horizontal/vertical bands) around them. Lack of such strengthening techniques may cause the structure to undergo severe damage during the seismic excitations. In this paper, the change in response of RC masonry infilled frames due to the presence of lintels and lintel bands above the openings is studied. For studying the behavior of the frames, static non-linear pushover analysis using Applied Element Method (AEM) based analysis tool has been used.

@inproceedings{bib_POUN_2014, AUTHOR = {Chandra Sekhara Reddy T, Kiran Kumar Reddy K, Pradeep Kumar Ramancharla}, TITLE = {POUNDING PROBLEMS IN URBAN AREAS}, BOOKTITLE = {International Journal of Research in Engineering and Technology}. YEAR = {2014}}

Buildings in urban areas and metropolitan cities are constructed very close to each other. This is because of the requirement of functional usage and high land value. Because of the insufficient gap between the adjacent buildings or adjacent units of the same buildings, they are most vulnerable for seismic damage like pounding. The adjacent land generally belongs to different land owners, where they construct the buildings for different requirements (residential, public). This leads to different dynamic properties of the adjacent buildings. During the earthquakes these may vibrate in or out-of-phase leading to damages, varying from slight architectural damages to severe structural damages. In this paper the pounding analysis is done for different cases of different building positions like buildings of same height and same floor level to buildings in row, are analyzed using SAP (2000) software package. When the two buildings are placed at different floor levels the impact force is more than buildings with the same floor levels. Also when buildings are in a row exterior building suffers more pounding damage than the interior building.

@inproceedings{bib_Mode_2014, AUTHOR = {PATNALA V S NEELIMA, Pradeep Kumar Ramancharla}, TITLE = {Modeling of combined behaviour of brick masornry infill and reinforced concrete frame}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2014}}

Centre for Earthquake Engineering, Brick mamasory is one of the oldest material used for the construction of load bering

@inproceedings{bib_Appl_2013, AUTHOR = {K. Jagan Mohan, Pradeep Kumar Ramancharla}, TITLE = {Applied Element Method to un- derstand Seismic phenomenon}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2013}}

Modern research in India on dams has entered a distinct phase subsequent to the damage to Koyna dam, located in hitherto considered stable continental part, due to an earthquake on 11th December, 1967 in Koyna district, India. Out of about 5,100 large dams in India, a significant number are in moderately high and high seismic zones. As such they may be prone to probable instability to the dam’s structure due to earthquake resultant impacts. Even though none of the dams other than Koyna got damaged in India due to high magnitude earthquake activity, since 1967, it is felt necessary to understand the behaviour of dams due to water load coupled with dynamics of faults that are present in the vicinity of the dam, as dam failures due to earthquake activity are reported from different parts of the world. In this paper, damage to Koyna dam due to a fault motion caused nearby has been studied. A concrete gravity dam is selected from the National Importance Dams of India. Structure-1(S1) as a concrete gravity dam with foundation and structure-2 (S2) as a concrete gravity dam with foundation and soil strata are numerically modeled using Applied Element Method (AEM). Displacement at the base of soil strata is given to generate reverse fault effect on the dam. Behavior of dam is studied by direct and sub-structure methods. In the direct method, the effect of fault motion on dam is studied in S2, by modeling dam at different locations on foot wall and hanging wall. In sub-structure method, free-field accelerations are recorded at different locations on foot wall and hanging wall while only the sub-structure is subjected to fault motion. The recorded accelerations on the surface are used as input to analyze super structure S1. Comparison on behavior of dam in models S1 and S2 is later drawn.

@inproceedings{bib_Comp_2013, AUTHOR = {Ehsan Vafaeihosseini, Azadeh Sagheb, Pradeep Kumar Ramancharla}, TITLE = {Computational Fluid Dynamics Approach for Wind Analysis of Highrise Buildings}, BOOKTITLE = {AWARDS, CONVENTION & CONSULTANTS COLLOQUIUM}. YEAR = {2013}}

Analysis and design of high-rise buildings for lateral load such as wind load and earthquake are the major issues which are playing significant role in recent decades. This paper describes a recent application of the computational fluid dynamics technique for wind analysis. Conventional wind analysis suggests wind tunnel experiment for arriving at the wind forces for a given structural form. As a case study a regular 38-story high-rise building (Jamieson place, Calgary Canada1) made of concrete with shear wall, built in downtown Calgary 2010 is selected. It is assumed that the building is located in highly seismic area. The design objective was to develop most cost-effective structural system while meeting building functionality goals and adhering to code requirement. The main structural design issues considered in this building are reviewed: Static analysis, Dynamic Analysis, Wind Analysis and Stability Analysis. Initial static and dynamic analysis is conducted in SAP and later wind analysis is conducted in Ansys as opposed to wind tunnel experiments. The building model is modeled in Ansys workbench and then the mesh file is imported to Ansys CFX for CFD simulation and analysis. After CFD analysis the wind forces on the building model are extracted in Ansys CFX-Post and imported to the structural model in SAP 2000 for the structural analysis.

@inproceedings{bib_A_St_2013, AUTHOR = {Rajaram Chenna, Ajay Pratap Singh, Pradeep Kumar Ramancharla, Bal Krishna Rastogi}, TITLE = {A Study on Comparison between Real and Synthetic Ground Motions of Uttarkashi Earthquake}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2013}}

For the assessment of risk of any area three components are necessary viz., Hazard, Exposure and Vulnerability. While most of the times Exposure and Vulnerability are easy to obtain compared to Hazard. For Hazard estimation, real ground motions are required. However, in highly seismic areas with less number of recorded ground motions, artificial ground motions are quite helpful. The estimation of strong ground motion parameters for a particular region can be done either by analytical methods or by numerical methods. Present work illustrates a comparative study of real and artificial ground motion generated for Uttarkashi earthquake. Midorikawa technique is used for generating strong ground motions at different locations. Ground motions records are considered at 13 stations during Uttarkashi earthquake. The synthetic ground motions are compared with recorded accelerograms at stations. The results of the analyses with both artificial and real accelerograms were compared in terms of site-transfer function, acceleration response spectrum and several strong motion parameters.

@inproceedings{bib_Nume_2013, AUTHOR = {K. JAGAN MOHAN, Pradeep Kumar Ramancharla}, TITLE = {Numerical Study on Concrete Gravity Dam Subjected to Fault Motion}, BOOKTITLE = {nternational Symposium on Advances in Earthquake Science}. YEAR = {2013}}

Lifeline structures like dams should always be designed for highest safety, resisting worst forces of nature. However, events that took place across the world proved how devastating an earthquake could be, particularly near-field. Landers (1992 – Mw 7.3), Northridge (1994 – Mw 6.7), Hyogoken-Nanbu (1995 – Mw 6.8) and few more events with near-field effects caused damage to different range of structures. Notable damage to Koyna dam due to Koyna earthquake (1967 – Mw 6.5), India and Shih-Kang dam due to Chi-Chi earthquake (1999 – MW 7.6), Taiwan, proved effects of near-field earthquakes can cause damage even to dams. In India there are several dams constructed near the active faults, which might suffer moderate to severe damage in an event of near-field earthquake. In this concern, a proper study should be done to understand the behavior of concrete gravity dam subjected to near-field earthquake caused by fault motion near the dam site. In the proposed study, a concrete gravity dam is selected from the National Importance Dams of India. Structure-1(S1) as a concrete gravity dam with foundation and structure-2 (S2) as a concrete gravity dam with foundation and soil strata are numerically modeled using Applied Element Method (AEM). Displacement is given at the base to generate reverse fault effect on the dam. Behavior of dam is studied by direct and sub-structure methods. In the direct method, the effect of fault motion on dam is studied in S2, by modeling dam at different locations on foot wall and hanging wall. In sub-structure method, free-field accelerations are recorded at different locations on foot wall and hanging wall while only the sub-structure is subjected to fault motion. The recorded accelerations on the surface are used as input to analyze super structure S1. Comparison is later drawn between S1 and S2.

@inproceedings{bib_MODE_2013, AUTHOR = {MOHD AHMED HUSSAIN, Pradeep Kumar Ramancharla}, TITLE = {MODELLING OF BURIED FAULTS USING APPLIED ELEMENT METHOD}, BOOKTITLE = {International Journal of Earthquake Engineering and Science}. YEAR = {2013}}

Recent ground-motion observations suggest that there is a considerable difference in surface-rupturing earthquakes and earthquakes due to buried faults. Near fault records for buried as well as surface fault earthquakes, in the distance range of less than 100 m from the faults are not available except for few cases. Therefore numerical simulation of ground motions for such near-fault situations for buried and surface fault earthquakes is necessary. In this paper the difference in ground motion due to buried faults and surface faults has been studied using 3D Applied Element Method. For the surface fault when the fault intersects the surface, a remarkable concentration of large ground acceleration in a very narrow region around the fault trace has been seen. The presence of the low velocity layer tends to reduce the particle velocity and rupture speed leading to the reduction in ground motion. The ground motion due to buried fault contains low frequency content there by giving greater response to long period structures. It has been seen that there is increase in peak ground acceleration value on the surface with the increase in the stiffness of the bedrock layer where the rupture takes place and increase in the strong ground motion with the decrease in the rise time of the slip applied at the base of the fault plane. This study explains some of the features of the buried fault earthquakes.

@inproceedings{bib_Micr_2013, AUTHOR = {BODIGE NARENDER, DASARI HIMA CHANDAN, Pradeep Kumar Ramancharla, Takano K}, TITLE = {Micro-tremor Response of Buildings in high Seismic Areas: A Case Study on RC Framed Building in Chandigarh, India Part II: Response of building}, BOOKTITLE = {International Engineering Symposium}. YEAR = {2013}}

The Indian Seismic Code IS: 1893-2007 indicates that about 60% of India’s land area is under threat of moderate to severe earthquake shaking. Also according to census 2011, number of houses exposed such high hazard is almost 80%. This is due to uneven population distribution. In order to find out the potential risk to housing for a city, it is necessary to evaluate Hazard (H), Exposure (E) and Vulnerability (V). Since, vulnerability of a building is combination of many factors like, planning, design, execution and maintenance; it is very difficult to assess the same for entire city. As a case study, a 3-storey RC framed building has been selected in the Union Territory of Chandigarh, which lies in high seismic area; and vulnerability of the same to nearby earthquakes is studied. Building vibration sensors (accelerometers) have been installed at appropriate locations on the building and data acquisition is done. In companion paper, data is acquired first by using micro-tremor observation system and later by using permanent sensors. In this paper, event accelerations recorded at the ground were normalized to earthquakes in zone IV and zone-V areas and response of the building is studied. Fragility curve has been developed for the building area.

@inproceedings{bib_Micr_2013, AUTHOR = {DASARI HIMA CHANDAN, BODIGE NARENDER, Pradeep Kumar Ramancharla, Takano K}, TITLE = {Micro-tremor Response of Buildings in high Seismic Areas: A Case Study on RC Framed Building in Chandigarh, India Part I: Response of building}, BOOKTITLE = {International Engineering Symposium}. YEAR = {2013}}

The Indian Seismic Code IS: 1893-2007 indicates that approximately 60% of India’s land area is under the threat of moderate to severe earthquake shaking. According to census 2011, number of houses exposed such high hazard is almost 80%. This is due to uneven population distribution. In order to find out the potential risk to housing in a city, it is necessary to evaluate Hazard (H), Exposure (E) and Vulnerability (V). Since, vulnerability of a building is a combination of many factors like, planning, design, execution and maintenance; it is very difficult to assess the same for entire city. As a case study, a 3-storey RC framed building, which lies in a highly seismic area, has been selected in the Union Territory of Chandigarh and its vulnerability to nearby earthquakes is studied. Building vibration sensors (accelerometers) have been installed at appropriate locations on the building and data acquisition has been done. In this paper, we present a comparison of Fourier amplitude spectrums generated from the data acquired using a micro-tremor observation system and permanent sensors. The companion paper presents a study of the response of the building to the acceleration data, recorded at ground, normalized to the earthquakes in zone IV. We then propose a potential risk model to the scenario earthquake by analyzing the fragility curve developed for the building area.

@inproceedings{bib_SSI__2013, AUTHOR = {SUSHMA P, Pradeep Kumar Ramancharla}, TITLE = {SSI Analysis of Framed Structures Supported on Pile Foundations : A Review}, BOOKTITLE = {Frontiers in Geotechnical Engineering}. YEAR = {2013}}

The post earthquake study of the structures reveals that the interaction of soil and foundation plays a major role in the damage/response of structure. In this regard a literature survey has been done on Frame structures supported on various foundations like isolated footings, mat foundations, combined footings or pile foundations. Persual of literature reveals that very few investigations were done on frame structures supported on pile foundations. So in this paper, an attempt is made to implement the prominent investigations on soil structure interaction analysis of framed structures supported on pile foundations. It also covers the analytical methods to predict lateral deflections of pile foundations alone (single and Group piles).

@inproceedings{bib_Fini_2013, AUTHOR = {Vasudeo Chaudhary, VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Finite element analysis of buried continuous pipeline subjected to fault motion}, BOOKTITLE = {International Journal of Structural Engineering}. YEAR = {2013}}

Abstract: Pipeline generally extends over long distances traversing through wide variety of different soils, geological conditions and regions with different seismicity. Most analytical models developed in the past for pipeline fault crossing are of limited usage as models developed were useful only for strike slip fault. Incorporating the large geometric changes in analytical study is a tricky task; however pipeline subjected to the fault motion itself is a phenomenon of large geometric changes, especially when pipeline subjected to compression in addition to material deformation, it also undergoes local buckling with bending. With computational advancement in numerical modelling, pipes under compression can also be studied. In this paper, a 3D FE-based numerical model is suggested to carry out pipeline performance of buried pipeline subjected to fault motion including material non-linearity and large geometric deformations. A 3D FE programme is developed using MATLAB. Displacement controlled arc-length technique is implemented to solve the non-linear behaviour.

@inproceedings{bib_Eart_2013, AUTHOR = {SREERAMA AJAY KUMAR, Pradeep Kumar Ramancharla}, TITLE = {Earthquake behavior of reinforced concrete framed buildings on hill slopes}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2013}}

Recent earthquakes, 18 Sep 2011, Sikkim earthquake, M6.9 and 1 May 2013 Doda earthquake, M5.8 produced two major effects, namely on buildings and on hill slopes. The maximum intensity of ground shaking experienced during these earthquakes was only about VI or less on the MSK scale. Considering the low intensity of ground shaking inthe affected areas, the damage attributed was disproportionately higher. It ismainly due to high amplification in local site areas. In this regard, a research is carried out to understand the performance of buildings on hill slopes. In this paper, the study of the behavior of a G+3 building on varying slope angles i.e., 15°, 30°, 45°and 60° is studied and compared with the same on the flat ground. Building is designed as per IS 456 and later subjected to earthquake loads. It was observed that as the slope angle is increasing, building is becoming stiffer. Two types of analyses were conducted viz., lateral load analysis and incremental dynamic analysis. It was observed from the initial results that the columns on the higher side of the slope i.e., short columns were subjected to more shear force then longer columns on the lower side. Finite element method is used to study the static behavior where as Applied Element Method (AEM) is used to perform incremental dynamic analysis.

@inproceedings{bib_Stud_2013, AUTHOR = {Rajaram Chenna, MOHD AHMED HUSSAIN, Pradeep Kumar Ramancharla}, TITLE = {Study on the Correlation between Shear & Rupture Wave Velocity of Chandigarh Fault}, BOOKTITLE = {Joint International Workshop on Geospatial Data for Disaster and Risk Reduction}. YEAR = {2013}}

Recorded large earthquake show that different sigment may reputre at different velocities.

@inproceedings{bib_Two__2013, AUTHOR = {JAYANTH KATURI, VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Two dimensional simulation of Tsunami wave propagation using MATLAB}, BOOKTITLE = {Joint International Workshop on Geospatial Data for Disaster and Risk Reduction}. YEAR = {2013}}

The M9.3 sumitra earthquake ot 26th december 2004 is due to largest recorded seismic event along Anadama- Sunda subduction zone.

@inproceedings{bib_Andr_2013, AUTHOR = {GUGAN VIGNESH S, Pradeep Kumar Ramancharla}, TITLE = {Android Based Application for Forest Fire Simulation Using 2D Cellular Automata}, BOOKTITLE = {Joint International Workshop on Geospatial Data for Disaster and Risk Reduction}. YEAR = {2013}}

Since many decades different ports of world's forest envirornment is getting depleted because of many other factors but major deplection due to random forest fires.

@inproceedings{bib_Less_2013, AUTHOR = {CVR Murthy, Ajay Chourasia, Hari Kumar, Anup Karanth, Pradeep Kumar Ramancharla}, TITLE = {Lessons from 1st May 2013 Doda (India) Earthquake Reiterate Urgent Need to Mitigate Seismic Risk}, BOOKTITLE = {Disaster and Development}. YEAR = {2013}}

The Doda Earthquake of 1st May 2013 at 12:27 Hrs. (IST) hit border region of two states of India (Jammu & Kashmir and Himachal Pradesh) (Mw= 5.8). This paper describes the findings of the 5-day post-earthquake reconnaissance survey undertaken in the affected areas with particular emphasis onbuilding typology, construction materials and construction practices. Post-earthquake damage assessment of the built environment suggests that recently built structures do not have adequate earthquake resistant featuresto resist severe earthquake shaking (of about IX on MSK scale) expected in the region. On the other hand, traditional constructions with good earthquake resistant features performed much better.The maximum intensity of shaking during the said event was only about VI on MSK scale, and the damage was less. But, the type of damage suggests that huge losses can be incurred in the region during a future earthquake of higher intensity, if the built environment is not retrofitted.

@inproceedings{bib_Eart_2013, AUTHOR = {K. JAGAN MOHAN, Pradeep Kumar Ramancharla}, TITLE = {Earthquakes and dams in India: an overview}, BOOKTITLE = {INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY}. YEAR = {2013}}

Dam is one of the biggest structures built on the Earth. It is known as a life line structure, as it serves the purpose of irrigation, hydro-electric power generation, flood control, domestic and industrial water supply etc., which are important for human existence. This makes dam as a reliable structure. For this reason, dam should always be designed for highest safety, resisting worst forces of nature. India is a country with over 5,100 large dams. India is also a seismically active country with over 1,040 active faults. Earthquake events like 1988 Bihar, 1991 Uttarkashi, 1993 Killari, 1997 Jabalpur, 1999 Chamoli, 2001 Bhuj, 2002 Andaman, 2004 Sumatra, 2005 Kashmir, and 2011 Sikkim have caused enormous loss of life and property in the country. Also events like 1992 Landers, 1994 Northridge, 1995 Hyogoken-Nanbu and few other events that took place around the world proved how devastating an earthquake could be, particularly if it is near-field. Near-field ground motions could cause more damaging effects on structures, as they were observed to differ dramatically from the characteristics of their far-field counterparts. The propagation of fault rupture towards a site at very high velocity causes most of the seismic energy from the rupture to arrive in a single or multiple large long period pulse of motion, which occurs at the beginning of the record. This characteristic of near-field ground motions could cause damage to a wide range of structures including dams. Several dams that were built in India, which are in highly seismic zones are prone to near-field ground motions. In

@inproceedings{bib_3D_F_2012, AUTHOR = {VENKATA DILIP KUMAR P, Vasudeo Chaudhary, Pradeep Kumar Ramancharla}, TITLE = {3D FE MODELLING OF BURIED CONTINUOUS PIPELINE EXPOSED TO FAULT MOTION WITH MATERIAL NONLINEARITY AND LARGE DEFORMATION}, BOOKTITLE = {International Conference on Structural Stability and Dynamics}. YEAR = {2012}}

Pipeline generally extends over long distances traversing through wide variety of different soils, geological conditions and regions with different seismicity. Majority of the past works in the area of pipeline subjected to fault motion is restricted in several ways. There were many analytical models developed in the past for pipeline fault crossing, however, they are of limited usage, for example analytical model developed for pipeline fault crossing can be useful for strike slip fault crossing only. Likewise incorporating the large geometric changes in analytical study is a tricky task; however pipeline subjected to the fault motion itself is a phenomenon of large geometric changes. Especially when pipeline subjected to compression, where in addition to material deformation it also undergoes general as well as local buckling with bending, contradictorily past work mostly assumed that pipeline is under tension. With day by day increasing capacity of computation and advancement in numerical modeling, one can find more facts for pipeline subjected fault motions including cases of pipe under compression as well. In this paper, past work is reviewed for pipeline subjected to large fault motion. A three dimensional FE based numerical model is suggested to carry out pipeline performance of buried pipeline subjected to fault motion. A proposed model includes material nonlinearity, as well as effect of the large geometric changes. For this purpose, three dimensional FE program is developed in MATLAB. Displacement controlled Arc-length technique is implemented to solve the nonlinear behavior. To reduce the computation time of analysis here parallelization tool kit of MATLAB is utilized.

@inproceedings{bib_THRE_2012, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {THREE DIMENSIONAL MODELING OF POUNDING BETWEEN ADJACENT BUILDINGS}, BOOKTITLE = {International Conference on Structural Stability and Dynamics}. YEAR = {2012}}

Pounding between adjacent structures is commonly observed phenomenon during earthquakes. In metropolitan areas, due to increasing population and land values buildings have been constructed very close to each other. Although seismic pounding between adjacent structures is considered in codal provisions, the practice of construction is still a problem in developing countries resulting more vulnerable during earthquakes. To study the effect of structural pounding, a case study has been done on different setbacks and storey heights of two adjacent structures using SAP 2000. The pounding responses of two structures and collision forces are calculated. The effect of collision is more when structures are kept at extreme levels of setback. When the structures are kept at different elevation levels (setback=0), the pounding response changes significantly as the height of structure decreases.

@inproceedings{bib_Comp_2012, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Comparison of Codal Provisions on Pounding between Adjacent Buildings}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2012}}

Abstract: Pounding between adjacent structures is commonly observed phenomenon during major earthquakes which may cause both architectural and structural damages. Generally most of the existing buildings in seismically moderate regions are built without codal provisions. In the event of earthquake, pounding may cause considerable damage and leads to collapse of the colliding structures if the separation distance is insufficient. The aim of this paper is to study the impact of first collision according to the codal provisions for five different earthquakes. For this purpose we considered two buildings and the same were idealized as linear single degree of freedom oscillators. Separation distance between buildings is provided accoding to codal provisions of various countries and the buildings are subjected to different ground motions of PGA ranging from 0.22 g to 0.88 g. Later impact force due to collision is calculation and the results were analyzed.

@inproceedings{bib_Poun_2012, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Pounding Between Adjacent Buildings: Comparison of Codal Provisions}, BOOKTITLE = {Indian Concrete Journal}. YEAR = {2012}}

It is not uncommon to find buildings in seismically active regions built adjacent to each other without following the prescribed codal separation distance. If the separation distance is insufficient, in the event of an earthquake, pounding may cause severe architectural and structural damage, and may even lead to the collapse of the structure. Seismic design codes suggest minimum separation distance between two adjacent structures; however, the spacing has to be enough to withstand earthquake excitations. To understand the effect of codal provisions on pounding, two buildings were idealised as linear single degree of freedom oscillators. The separation distance between them was provided following the codal provisions of select countries. By subjecting the buildings to five different ground motions the first impact force due to collision was calculated and the results were analysed to compare the codal provisions.

@inproceedings{bib_Disp_2012, AUTHOR = {Anthugari Vimala, Pradeep Kumar Ramancharla}, TITLE = {Displacement Based Damage Estimation of RC Bare Frame Subjected to Earthquake Loads: A Case Study on 4 Storey Building}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

Reinforced concrete buildings constitute the dominant type of construction in the earthquake prone countries. Many researchers have studied the performance of the RC structure in seismic environment. In this study a RC building of four storeys is considered and its performance is evaluated when subjected to five ground motions. The study is roughly divided into three parts, first part includes investigation of the dynamic characteristics of ground excitations, second part includes evaluation of the nonlinear seismic behaviour of building subjected to the given ground excitations and third part includes evaluation of damage. The present study is based on analytical investigation of seismic performance and potential seismic damage of a reinforced concrete framed building due to earthquakes in India, using nonlinear modelling and displacement-based analysis techniques. Since the seismic damage is directly correlated to the displacement (deformation) of the structure, the yield displacement of the structure is evaluated from the pushover analysis. From the displacement time history of the structure response, the peak values which exceeding yield displacement of the structure have been identified and the hysteresis energy is calculated for each cycle to calculate the damage of the structure. The estimation of structural damage is calculated as per the model of Park and Ang. At the end, authors attempted to propose a new damage scale.

@inproceedings{bib_Inel_2012, AUTHOR = {ARCHANAA DONGRE, Pradeep Kumar Ramancharla}, TITLE = {Inelastic Response of RC Moment Resisting Frames with URM Infills}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

Brick masonry type of construction is found all over India and neighbouring countries like Nepal and Bangladesh. In India, these buildings are commonly found in North, extending from Punjab to West Bengal and Central India, from Haryana to Madhya Pradesh. These buildings are most commonly found in regions where good quality clay for brick production is abundantly available (World housing encyclopaedia report, 2003). But, past earthquakes witness major loss to brick masonry type of buildings. Many analytical and experimental studies have been done in past to understand the behaviour of brick masonry buildings during earthquake. Analytical study mainly includes, numerical modelling of the brick masonry buildings of type URM and Reinforced concrete Infill wall. In this work, primary focus is given to numerical modelling and nonlinear behaviour of brick masonry buildings subjected to lateral loads and understanding crack propagation in wall and calculation of quantitative damage to the building in terms of stiffness, ductility in load displacement curve.

@inproceedings{bib_3D_N_2012, AUTHOR = {Vasudeo Chaudhar, VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {3D Nonlinear Modeling of Buried Continuous Pipeline Subjected to Ground Compression}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

Pipeline generally extends over long distances traversing through wide variety of soil conditions with different seismicity. Majority of past work mainly restricted to pipelines exposed to strike slip fault motion or transverse permanent ground deformation that too cases of pipelines under tension. The study of buried pipeline under compression is of extreme importance, especially pipelines passing through thrusting sub-continent like India, where majority of pipelines are exposed to compression. In compression pipelines fail in material as well as in geometry. In this paper past work is reviewed and 3D finite element based model is proposed to compare pipeline performance subjected to different types of ground motion. The proposed model includes material non-linearity as well as effect of large geometric changes. In this proposed model displacement control Arc-length technique is implemented to solve the nonlinear behavior. To reduce the computational time of analysis a parallelization tool kit of MATLAB is utilized.

@inproceedings{bib_Stud_2012, AUTHOR = {Rajaram Chenna, Pradeep Kumar Ramancharla}, TITLE = {Study on Impact Between Adjacent Buildings:Comparison of Codal Provisions}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

Structures are being built very close to each other in metropolitan areas where the cost of land is very high. Due to closeness of the structures, they often collide with each other when subjected to earthquakes. Many studies have been carried out on separation distance between adjacent structures to mitigate pounding. Although some modern codes included seismic separation requirement for adjacent structures, some of them have failed in providing the appropriate minimum separation distance. In this paper, two linear single degree of freedom oscillators are used to study the impact force for five different ground motions ranging from 0.2 g to 0.8 g. The separation distance is calculated from the codal provisions of different countries. The separation distance between the two structures decreases, the amount of impact increases which is applicable when the impact time is same. It may also decreases when separation distance decreases. For structures having same period, no need to provide separation distance. The amount of impact depends on response of the structures at particular time, minimum space between the structures and velocity of the structures.

@inproceedings{bib_Stru_2012, AUTHOR = {Abhishake Munipala , VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Structural Dynamics Virtual Laboratory: A Learning Tool Kit for Young Engineers and Practicing Professionals}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

India has been facing earthquake problems from many centuries which need no introduction. From recent earthquakes, it is very well understood that lack of awareness is one of the major factor for huge casualty losses. While still having the probability of occurrences of earthquakes in India, it becomes very important and need to increase the awareness about the effects of earthquakes among growing professionals involved in construction by making them understanding the concepts of Structural Dynamics and Earthquake Engineering. This paper will detail the use of virtual laboratory in real time environment of structural dynamics. Virtual Laboratory provides a new methodology to convey and learn concepts using the power of visualization of ideas and computations. Virtual labs rely on an active engagement of the learner in the knowledge acquisition process. This paper is aimed at promoting the new methodology and providing a glimpse into the exciting world of interactive and experimentation of structural dynamic concepts with no limitation of conductance. Using this tool, a person with little knowledge of structural engineering can enhance his fundamentals of structural dynamics. For better understanding experiments are explained with graphical diagrams seen in GUI with the support of JAVA 3D. Apart from basic understanding of dynamic behavior of structure, this tool kit also helps architects and young civil engineers in understanding the principles of structural dynamics.

@inproceedings{bib_A_Me_2012, AUTHOR = {CVR Murty, Durgesh Rai, Hari Kumar, Keya Mitra , Amit K. Bose , Hemant B. Kaushik, Arvind Jaiswal , Pradeep Kumar Ramancharla}, TITLE = {A Methodology for documenting Housing Typologies in the Moderate-Severe Seismic Zones}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

The paper presents first-cut of the salient findings and inferences of a pilot study of housing sub-typologies practiced in seven locations in moderate to severe seismic zones in India. Field trips were conducted to understand housing approaches, methods and constraints employed in 7 locations of the moderate-to-severe seismic zones of India. Based on these field trips, the following deliverables are offered:(1) A methodology for technical documentation of housing typologies in moderate-to-severe seismic zones, through documentation of all safety-related information of an individual house; and (2) A base-level Technical Evaluation Method of earthquake safety of a house for the prevalent earthquake hazard at the location of the house. This method provides both Seismic Safety Index and Performance Rating Method for benchmarking an individual house with respect to an ideal house of the same typology built to resist earthquake shaking in the same seismic environment.

@inproceedings{bib_Nume_2012, AUTHOR = {SUSHMA P, Pradeep Kumar Ramancharla}, TITLE = {Numerical Modeling of Interface Between Soil and Pile to Account for Loss of Contact during Seismic Excitation}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2012}}

This paper presents a methodology to understand the interface behavior of soil and pile under transient loading. Previous works by Trochanis (1991), Bently and Naggar (2000) and others gave an insight to the problem. But this paper illustrates the research methodology developed to understand the dynamic behavior of pile and soil by taking the soil yielding effects and also the interface effects. A detailed parametric study has been done to understand the behavior of the same by varying the length of the pile for various soil conditions. For the purpose of comparison, soil model size was taken as 15m x 10m x 11m with pile cross section as 0.5 X 0.5 m and length of pile as 10m. For this we have developed a program for modeling the soil pile structure interaction using three dimensional Finite Element Method in MATLAB R2009a, the details of the same have been given in this paper along with the validity of it with benchmark problems in the literature.

@inproceedings{bib_Asse_2012, AUTHOR = {BODIGE NARENDER, Raghavender Baroda, Pradeep Kumar Ramancharla}, TITLE = {Assessment of Capacity of Existing Building Through Nonlinear Static Pusover Analysis A Comparison between Micro and Macro Modeling}, BOOKTITLE = {National Conference on Advances in Earthsciences, Structural, Geotechnical and Earthquake Engineerin}. YEAR = {2012}}

extensive damage Occurred in non engineered structure..Many casualities occured in stone masonary buildings

@inproceedings{bib_Push_2012, AUTHOR = {BODIGE NARENDER, Pradeep Kumar Ramancharla}, TITLE = {Pushover Analysis of RC Bare Frame: Performance Comparison between Ductile and Non-ductile Detailing}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2012}}

The objective of this paper is to compare pushover response of ductile and non-ductile frames using AEM (Applied Element Method). Pushover analysis is non linear static analysis, a tool for seismic evaluation of existing structures. Unlike FEM, AEM is a discrete method in which the elements are connected by pair of normal and shear springs which are distributed around the elements edges and each pair of springs totally represents stresses and deformation and plastic hinges location are formed automatically. In the present case study a 1 x 1 bay four storied building is modeled using AEM. Gravity loads and laterals loads as per IS 1893-2002 are applied on the structure and designed using IS 456 and IS 13920. Displacement control pushover analysis is carried out. The effect of ductile detailing, change in grade of concrete and bar sizes in columns is also compared.

@inproceedings{bib_COMP_2012, AUTHOR = {Archanaa Dongre, Pradeep Kumar Ramancharla}, TITLE = {COMPARATIVE STUDY OF INELASTIC BEHAVIOR OF RC FRAME WITH AND WITHOUT BRICK INFILL USING APPLIED ELEMENT METHOD}, BOOKTITLE = {Golden Jubilee Symposium on Earthquake Engineering}. YEAR = {2012}}

Construction practices in major part of rural as well as suburban areas in India uses brick masonry type of buildings; this may be due to easy availability of material, aesthetic appeal and cost effective. Such type of construction is also found in nearby areas like Nepal and Bangladesh. In India, these buildings are most commonly found in regions where good quality clay for brick production is abundantly available (World housing encyclopaedia report, 2003). In past studies it has been found that brick quality is comparatively better in north part of India than south, this is due to good quality of soil in north India. But, such type of buildings proved to be vulnerable during past history of earthquake. Though, past experimental and analytical studies stress upon understanding behaviour of brick masonry buildings, this numerical study has advantage over others that it can show initiation of crack, gradual propagation of cracks till the total collapse of building. In this parametric study, four cases have been considered and effect of considering infill and without infill on strength, stiffness and ductility of wall has been studied.

@inproceedings{bib_Nonl_2012, AUTHOR = {Harinadha Babu.R, Pradeep Kumar Ramancharla}, TITLE = {Nonlinear Static Large Deformation Analysis of Bare Frames Subjected to Lateral Loads}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2012}}

Overall capacity of a structure depends on the strength and deformation capacities of the individual component of the structure. In order to determine capacities beyond the elastic limits some form of nonlinear analysis such as the pushover procedure is required. This procedure uses a series of sequential elastic analyses, superimposed to approximate a force-displacement capacity diagram of the overall structure. Usually this analysis is performed using FEM and that too with major assumption in defining hinge mechanisms and target displacement. In this paper, a new method for analysis nonlinear static large deformation analysis of bare frame subjected to lateral load is proposed. First we developed the method and later four frames were taken and they were pushed up to failure. Results clearly show the capability of the proposed method.

@inproceedings{bib_Nume_2011, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Numerical Simulation of Tsunami Wave Propagation in Indian Ocean}, BOOKTITLE = {International Journal of Computational Modeling,}. YEAR = {2011}}

This paper aims to simulate the Tsunami wave propagation in Indian Ocean. The simulation is done using OPENGL (Open Graphics Library) in Linux. The Analysis area covers from 8.15 degrees (-ve North) to 26 degrees (+ve north) and 71.72 degrees (+ve East) to 104.78 degrees (+ ve East). The Bathymetry data and Grid map are derived from GEBCO (General Bathy-metric Chart Of Oceans). The Bathymetric Grid Map is divided in the form of Grids. The Grid Map using OPENGL is scaled, transformed and displaced to get the depth value corresponding to the point which is assumed as epicentre.

@inproceedings{bib_2D_N_2011, AUTHOR = {BODIGE NARENDER, Pradeep Kumar Ramancharla}, TITLE = {2D Numerical Modeling of Progressive Collapse During Earthquakes: A Case Study on RC Bare Frame}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2011}}

Earthquake performance of RC bare frame has been well documented in the past. Also, damage patterns in reinforced concrete frames during the past earthquakes have been extensively studied. However, more recently, several destructive earthquakes, including the 1999 Athens (Greece) earthquake, the 1999 İzmit and Düzce earthquakes (Turkey), 1999 Chi Chi (Taiwan) earthquake, 2001 Bhuj (India) earthquake, and the 2003 Boumerdes (Algeria) earthquake, have given more insights to performance of RC frame constructions. In order to understand the complete behavior of RC frame, it is required to study the performance from no loading condition till the complete collapse. In this paper, a set of four bare frames designed as per Indian Standards are considered. All the frames are subjected to Northridge earthquake ground motion. Newly developed numerical model called Applied Element Method (AEM) is considered for analysis. Initially, the linear analysis is carried out and the results were compared with commercially available software. Later, progressive collapse analysis is performed. Collapse process of each bare frame is discussed in detail.

@inproceedings{bib_DYNA_2011, AUTHOR = {PRANEETHA SURAPANENI, Pradeep Kumar Ramancharla}, TITLE = {DYNAMIC ANALYSIS OF PRESSURISED HEAVY WATER REACTORS}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2011}}

Water Reactors are nuclear power plants that use water to control and remove the heat from the nuclear fuel in order to convert heat to electricity. In this report, we have considered the number of nuclear reactors and their locations in our country. Among all those nuclear reactors, we selected the nearest kalpakkam reactor which is located in Chennai, India. All the faults, around 500 kms from the reactor are considered. From the past history of earthquake data (1812-2002), we considered the maximum magnitude of each fault and source parameters for some faults has been determined. The soil liquefaction characteristics of a site and the procedure for generating Synthetic accelerogram using the Stochastic Method Simulation of ground motion from earthquakes (SMSIM) have been discussed. For performance evaluation, a 3-dimensional model of the dome was taken and dynamic (Time History analysis) was performed to evaluate the displacements at each floors. A 3-dimensional model of the dome was modeled in computer program SAP2000 and Dynamic (time history) analysis was performed on the structure to evaluate the structure's response. The model was analyzed for the earthquake ground motion obtained from SMSIM.

@inproceedings{bib_DISA_2011, AUTHOR = {Lakshmi Tejaswi , Pradeep Kumar Ramancharla}, TITLE = {DISASTER MITIGATION AND MANAGEMENT FOR ANDHRA PRADESH, INDIA: AN APPRAISAL}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2011}}

Every year in the country innumerable number of life and property is getting lost in the disasters. Pre-disaster planning i.e., mitigation and preparedness can have a good impact on minimizing the post-disaster response i.e., emergency, rescue and rehabilitation. This also reduces tragedy and suffering to a great extent. Andhra Pradesh being 4th largest state in India by area of 2,75,608 km² and 5th largest in population with over 100 million and a density of 277 persons/km2 is spread over 23 districts. Although it lies in the central part of peninsular Indian shield it has prone to many disasters which caused large number of casualties and innumerable property loss. This paper discusses the disasters like cyclone, floods, drought, earthquakes, tsunami, fire, etc., with statistics relevant to each disaster. Finally, we recommend the effecient strategies for disaster risk mitigation.

@inproceedings{bib_Line_2011, AUTHOR = {Harinadha Babu Raparla, Pradeep Kumar Ramancharla}, TITLE = {Linear Analysis of Reinforced Concrete Buildings Subjected to Blast Loads}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2011}}

In the past there were many terrorist attacks on buildings. Also the threat of such kind of attacks is increasing day-by-day. After the progressive collapse of the Roman Point apartment, England in 1968, structural engineering research departments throughout the world forced to direct their research towards the progressive collapse of highrise buildings under abnormal loads. Many guidelines, standards and criteria were developed across the world. Such guidelines are necessary for construction of blast resistant buildings. However, in addition to these guidelines, it is necessary to understand the progressive collapse process of the building under the action of heavy impact load. In this paper, we studied the linear responses of different RC bare frames for different ranges and charge weights according to different blast loads. Initially, the blast loads over the frames are calculated for for different ranges and charge weights according to TM 5-1300 9. Later these loads are applied on the bare frames taken from the structures which are designed for the normal gravity and lateral loads. Four fames (one story one bay, three story one bay, five story one bay and ten story-three bays) are considered. For the purpose of the study, highly efficient numerical model AEM is used. Results clearly show that the even though the charge weight of the blast is increasing the response is not increasing linearly. Also the response is low for heavy structures compared to lighter structures.

@inproceedings{bib_Eart_2011, AUTHOR = {Raju Sangam, T Sreekanth, Pradeep Kumar Ramancharla}, TITLE = {Earthquake Disaster Safety and Preparedness A Pilot Project in Hyderabad City, India}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2011}}

Earthquake problems in India need no introduction. Some of the great earthquakes of the world occurred in India and neighbourhood areas. During past two decades, India has witnessed 7 moderate earthquakes which caused large number of casualties and innumerable property loss. Most of these losses are due to poor quality of construction and generally low level of awareness of the earthquake hazard prevalent in the country. In this regard, there is a need for coordinated and sustained effort towards earthquake risk reduction in the country. This can be achieved through education and awareness building. In general, sensitization programmes are required to build awareness at all levels, however, it is most important at school level because they prepare the future generations from early age. It is necessary to prepare simple reading material so that children can understand the problems at an early age itself. In this paper, we are discussing our effort in organizing earthquake day in 50 schools. Initially 50 schools in Hyderabad city were selected and on an average around 100 school children ranging from 8th to 10 standard were sensitized in each school. Total duration of the programme was 18 months. On school earthquake day, planned activities are as follows: Session I Introduction to earthquakes through animated short videos Session II Explanation of awareness generating experimental models Session III Explanation of information posters related to disaster preparedness Session IV Explanation of preparation of earthquake safety kits Session V Earthquake quiz and puzzle games related to disasters The models and material used for demonstration was given to school for their future use. Overall the programme was successful and we received excellent feedback from schools.

@inproceedings{bib_Eart_2011, AUTHOR = {K. RENUKA DEVI, SILPA CHOWDARY SADINENI, T. ASHWINI REDDY, Pradeep Kumar Ramancharla}, TITLE = {Earthquake Response of Light Houses in Gujarat Coast}, BOOKTITLE = {National Conference on Recent Trends in Civil and Mechanical Engineering}. YEAR = {2011}}

During past earthquakes there were some notable instances of collapse of light houses near gujarat coast. These damages can be minimized by proper evaluation of seismic hazard based on past history of earthquakes in the region. During Bhuj, 26th Jan 2001 earthquake of magnitude 7.9Mw, some structures have damaged a lot while others have little, the behavior of light house during earthquakes depends critically on its overall shape, size and geometry in addition to how the earthquake forces are carried to the ground. In this regard, we attempted to check the earthquake response of light houses of different geometries. For this purpose we selected three different light houses of three different shapes (square, hexagon, octagonal) of same height. All the three light houses are modeled using SAP 2000 and dynamic analysis is performed. Each light is subjected to ten different earthquake ground motions and responses are compared

@inproceedings{bib_The__2011, AUTHOR = {Azadeh Sagheb, Ehsan Vafaeihossein, Pradeep Kumar Ramancharla}, TITLE = {The Role of Building Construction Materials on Global Warming Lessons for Architects}, BOOKTITLE = {National Conference on Recent Trends in Civil and Mechanical Engineering}. YEAR = {2011}}

The world today has encountered with global warming and climate change. Besides other contributors, extraction of natural resources as building materials itself consume energy, cause environmental degradation and contribute to global warming. Buildings are the largest energy consumers and greenhouse gases emitters, both in the developed and developing countries. Urgent changes are therefore required relating to energy saving, emissions control, production and application of materials. Immediate suggestion related to use of renewable resources, and to recycling and reuse of building materials is necessary. This paper describes how much a typical building is contributing to global warming by releasing the carbon dioxide emission. And how the architects and building designers can decrease the amount of carbon footprint emitted from the building materials. As a case study a 3-story building made of commonly used materials; concrete, brick, stone and glass has been selected. Total quantity of carbon emission is estimated and finally suggestions are given to reduce carbon dioxide emission.

@inproceedings{bib_ASSE_2011, AUTHOR = {Praneetha Surapaneni, Pradeep Kumar Ramancharla}, TITLE = {ASSESSMENT OF VULNERABILITY OF INSTALLATION NEAR GUJARAT COAST VIS-À-VIS SEISMIC DISTURBANCES EARTHQUAKE (A CASE STUDY ON PIPAVAV PORT BUILDING}, BOOKTITLE = {IndianYoung Geotechnical Engineers Conference}. YEAR = {2011}}

The main objective of the project is Vulnerability Assessment of Port buildings in different port regions along west coast of India. It includes development of earthquake scenario and fragility curves, which describes in detail the effects and consequences of a hypothetical earthquake at that region. In this paper the plan, elevation and design details of the port building near the Pipavav port is mentioned. For performance evaluation, a 3-dimensional model of the structure was generated. Analysis and design is performed on the structure. Pushover analysis is done for each earthquake data, and the graph is plotted for displacement vs load and displacement vs stiffness. Hence stiffness degradation for each earthquake data for its maximum displacement is determined and fragility curve is developed for the port building. A 3-dimensional model of the structure was modeled in STAAD.Pro and seismic base shear is calculated for the structure using the IScode 1893 (Part1:2002) and the linear time history analysis is carried out on the structure.

@inproceedings{bib_Anal_2011, AUTHOR = {Ehsan Vafaeihosseini, Azadeh Sagheb, Pradeep Kumar Ramancharla}, TITLE = {Analysis of Highrise Building using Computational Fluid Dynamics Approach: A Case Study on 38-Storey Highrise Building}, BOOKTITLE = {Structural Engineering World Congress}. YEAR = {2011}}

Analysis and design of high-rise buildings for lateral load such as wind load and earthquake are the major issues which are playing significant role in recent decades .This paper describes a recent application of the computational fluid dynamics technique for wind analysis. Conventional wind analysis suggests wind tunnel experiment for arriving at the wind forces for a given structural form. As a case study a regural 38-story high-rise building (Jamieson place, Calgary Canada) made of concrete with shear wall ,built in downtown Calgary 2010 is selected. It is assumed that the building is located in highly seismic area. The design objective was to develop most cost-effective structural system while meeting building functionality goals and adhering to code requirement. The main structural design issues considered in this building are reviewed: Static analysis, Dynamic Analysis, Wind Analysis and Stability Analysis. Initial static and dynamic analysis is conducted in SAP and later wind analysis is conducted in Ansys as opposed to wind tunnel experiments. The building model is modeled in Ansys workbench and then the mesh file is imported to Ansys CFX for CFD simulation and analysis. After CFD analysis the wind forces on the building model are extracted in Ansys CFX-Post and imported to the structural model in SAP 2000 for the structural analysis.

@inproceedings{bib_Impa_2011, AUTHOR = {Pradeep Kumar Ramancharla, Sudhakar P, Narain Medury}, TITLE = {Impact of Bamboo on Sustainable Development of Urban and Rural India}, BOOKTITLE = {CFSD & ISTA Round Table meet}. YEAR = {2011}}

Presently India is home for about 1.2 billion people. This suggests that about 300 million houses are necessary to house them. According to National Housing Policy 2007 (NUHHP, 2007), the housing shortage is estimated to be about 25 million. And according to 2001 Census (Census 2001), Indian urban population constitutes 27.8%. However, it is increasing at an alarming rate of 4% per year. Further, population in India is distributed unevenly with minimum of 50 persons per km2 in some districts and upto 14000 persons per km2 in some other districts. Rural districts have upto 100 houses per km2 , towns 1000-1500 houses per km2 , cities 1500-2500 houses per km2 and urban centres and metros have as high as 7000 houses per km2. In addition, there is a great shift of population from rural to urban areas thus increasing the densities of population in urban areas. The number and proportion of cities with a population of one million or more has grown significantly in recent decades. From 12 in 1981 with 26.8% share of the total population, the number of million-plus cities has increased to 35 in 2001 with 37% share of the total urban population. On the other hand the dominant materials of choice for building were

@inproceedings{bib_Rapi_2011, AUTHOR = {Ajay Pratap Singh, Santosh Kumar, Pradeep Kumar Ramancharla, Bal Krishna Rastogi}, TITLE = {Rapid Visual Survey of Existing Buildings in Gandhidham and Adipur Cities, Kachchh, Gujarat}, BOOKTITLE = {International Symposium on the 2001 Bhuj Earthquake and Advances in Earthsciences and Engineering}. YEAR = {2011}}

Bhuj earthquake of 26 January 2001 caused 14,000 casualties. Main reason for such huge casualties is low earthquake awareness and poor construction practices. Based on the technology advancement and knowledge gained after earthquake occurrences, the seismic code is usually revised. Last revision of IS 1893 (Criteria for earthquake resistant design of structures) was done in 2002 after a long gap of about 18 years. Some new clauses were included and some old provisions were updated. Assuming that concerned authorities will take enough steps for code compliance and the structures that are being constructed are earthquake resistant. In this light, what will happen to the safety of precode revision structures? These structures carry major percentage of vulnerable structure stock. Even if we have a very good disaster response system, it is impossible to reduce earthquake damage without considering the safety of precode revision structures. In this regard, a comprehensive study of seismic risk assessment of Gujarat is necessary. As a pilot study, government of Gujarat selected Gandhidham and Adipur cities in Kachchh district. Rapid Visual Screening (RVS) was conducted on 16000 buildings in Gandhidham and Adipur cities. Though, there are varied construction practices, about 26% of buildings were predominantly RCC type and 74% of masonry structure were found. RVS score of these structures reveal that in general buildings are of low quality and further evaluation and strengthening of buildings is recommended. The procedure adopted in this study is threetier method, i.e., Tier 1. Rapid Visual Screening, Tier 2. Preliminary assessment and Tier 3. Detailed assessment

@inproceedings{bib_REVI_2011, AUTHOR = {Sai Sumanth Reddy, Pradeep Kumar Ramancharla}, TITLE = {REVIEW OF NUCLEAR ENERGY DEMAND IN URBANAREAS OF INDIA; VIS-À-VIS SESMIC DISTURBANCES}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2011}}

Disaster Demand for electricity in urban areas is increasing world over, because electricity is the prime lifeline support. Due to increase in fossil fuel prices coupled with concerns related to global warming, demand for nuclear energy is increasing. Around 30 countries are now using nuclear energy for production of electricity. However, its share in electricity production is varying from country to country. In some countries it is only 3% and in some countries it is around 50%. In light of March 2011 nuclear energy are reviewing the safety of their reactors against natural disasters. In this regard, authors proposed to study the current and projected nuclear energy demand for electricity supply in urban areas of India on one hand and scenario of seismic hazard and risk on the other hand.

@inproceedings{bib_Nume_2011, AUTHOR = {DASARI HIMA CHANDAN, Pradeep Kumar Ramancharla}, TITLE = {Numerical Simulation of Wind Analysis of Tall Buildings: Computational Fluid Dynamics Approach}, BOOKTITLE = {Indian Concrete institute}. YEAR = {2011}}

Building construction in India has been on rise since last two decades. More recently construction of tall buildings ranging from 30 to 50 stories have been proposed in many cities. For these buildings, wind analysis is as important as earthquake analysis, since in taller buildings, wind loads are dominant than earthquake loads at greater heights. In India, wind analysis is done according to IS 875 (Part III)-1987 (here after IS 875). But this code doesn’t provide sufficient information analysis of different structural forms. Quite often, engineers generally rely wind tunnel experiments to understand the behaviour. However, for arriving at the best orientation several tests have to be conducted which is tedious job. In the paper a necessity to adopt a different approach such as wind tunnel experiments and CFD simulation is proposed. Case study on wind analysis of Y-shaped tall building is illustrated using Ansys CFX and SAP 2000.

@inproceedings{bib_Thre_2011, AUTHOR = {Vasudeo Chaudhari, VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Three Dimensional FE Modeling of Buried Continuous Pipeline Exposed to Fault Motion}, BOOKTITLE = {International Conference on Current Trends inTechnology}. YEAR = {2011}}

Pipeline generally extends over long distances traversing through wide variety of different soils, geological conditions and regions with different seismicity. Majority of the past works in the area of pipeline subjected to fault motion is restricted in several ways. There were many analytical models developed in the past for pipeline fault crossing, however, they are of limited usage, for example analytical model developed for pipeline fault crossing can be useful for strike slip fault crossing only. Likewise incorporating the large geometric changes in analytical study is a tricky task; however pipeline subjected to the fault motion itself is a phenomenon of large geometric changes. Especially when pipeline subjected to compression, where in addition to material deformation it also undergoes general as well as local buckling with bending, contradictorily past work mostly assumed that pipeline is under tension. With day by day increasing capacity of computation and advancement in numerical modeling, one can find more facts for pipeline subjected fault motions including cases of pipe under compression as well. In this paper, past work is reviewed for pipeline subjected to large fault motion. A three dimensional FE based numerical model is suggested to carry out pipeline performance of buried pipeline subjected to fault motion. A proposed model includes material nonlinearity, as well as effect of the large geometric changes. For this purpose, three dimensional FE program is developed in MATLAB. Displacement controlled Arc-length technique is implemented to solve the nonlinear behavior. To reduce the computation time of analysis here parallelization tool kit of MATLAB is utilized.

@inproceedings{bib_Eart_2010, AUTHOR = {DINESH SINGH YADAV, Puneet Girdhar, VINAY KUMAR, Pradeep Kumar Ramancharla}, TITLE = {Earthquake Vulnerability of Free Standing Monolithic Statues}, BOOKTITLE = {European Journal of Scientific Research}. YEAR = {2010}}

Heritage structures bears a valuable testimony of ancient cultural heritage of any country. Among these structures statues, iconic emblems plays significant role. In the proposed to study the vulnerability of monolithic statues to earthquake ground motions. Initially we used the equations developed by Housner for studying the dynamics of rigid blocks. Parametric study was conducted to study the inuence of size of the block and input parameters such as amplitude and frequency on the behaviour of the block. The study was extended to generate safe surface for the block of given dimensions. This surface gives the information that with any combination of parameters such as amplitude of vibration, frequency of vibration and duration of vibration, if the point lies outside the surface then block overturns otherwise it is safe. To verify the above formulation we selected four statues, viz, Gomateswara statue, Christ the Redeemer, Statue of Liberty, Guinyin Statue for case study. Initially all the statues were idealized like rigid blocks and later safe surfaces were developed for each statue. Since each statue is having different dimensions, surfaces were are also of different nature. Later, eighteen earthquake records were selected and strong ground motion parameters were estimated. Finally every statue was tested for the safety during the earthquake events. It was found that as the height of the statue is increasing its vulnerability is increasing. However, for all the given ground motions, none of the statue overturned.

@inproceedings{bib_Basi_2010, AUTHOR = {Harinadh Babu.R, V.David Raju, Pradeep Kumar Ramancharla}, TITLE = {Basic Guidelines for the Determination of Blast Wave Parameters for Different Blast Environments}, BOOKTITLE = {Indian Concrete Institute Journal}. YEAR = {2010}}

Many countries have become victims of terrorism on a large scale. Bombs have exploded in and around buildings in many countries causing civilian causalities and structural damage. A bomb explosion with in or around a building can have catastrophic effects, damaging and destroying internal or external portions of the building. Bomb damage to buildings depends on the type and layout of the structure, material used, range of the located explosive device and the charge weight. The impact from the blast causes debris, fire and smoke and hence can result in injury and death of occupants. Escape of the occupants and protection of the valuable documents, equipments, property is possible only when there is minimum damage to structures. This may be achieved by designing the building structures for blast loading. This attempt gives basic idea to all the consultants in estimating the blast loads over the building structures.

@inproceedings{bib_AMPL_2010, AUTHOR = {P.SUSHMA, MOHD AHMED HUSSAIN, Pradeep Kumar Ramancharla}, TITLE = {AMPLIFICATION STUDIES OF LOCAL SOILS USING APPLIED ELEMENT METHOD}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2010}}

The amplification of ground motion is being observed during major earthquake events all over the world and is highly dependent on the local geological, topography and geotechnical conditions. In view of this there is a great need to study the local site effects in a seismically active region. In this paper, the numerical modeling of infinite media is carried out by using transmitting boundary condition. Wave interaction with different kinds of boundaries like fixed and viscous boundary is discussed. The heterogeneities in the soil media are taken into account by considering the soft clay and the rock inside the half-space. Peak ground acceleration at the surface is plotted and local amplification of soils is studied by giving Elcentro ground motion as input at the bed rock for both the cases. In the half-space where clay is present, PGA is amplified by a factor of 2.5 with respect to input. More energy is concentrated in the half-space where clay is present. In the half-space where rock is present the area adjacent to the rock is getting amplified as energy is concentrated around the rock.

@inproceedings{bib_Nume_2010, AUTHOR = {Neelima Satyam, Pradeep Kumar Ramancharla}, TITLE = {Numerical analysis of a Pile Subjected to Lateral Loads}, BOOKTITLE = {European Conference on Numerical Methods in Geotechnical Engineering}. YEAR = {2010}}

In the case of foundations of bridges, transmission towers, offshore structures and for other type of huge structures, piles are also subjected to lateral loads. This lateral load resistance of pile foundations is critically important in the design of structures under dynamic loading. Load carrying capacity and load deformation behavior of a single pile and group of piles subjected to lateral load is obtained using nonlinear finite element method of analysis. According to Poulos and Davis (1980) the maximum deflection of the pile is the major criterion in its design and made the initial attempts to study the lateral behavior of piles included twodimensional finite element models in the horizontal plane. Several investigations have attempted to study the behavior of pile under lateral load using 3D finite element analysis. In this paper a detailed study on the piles subjected to lateral loads are investigated.

@inproceedings{bib_Nume_2010, AUTHOR = {CHAUDHARI VASUDEO GOVIND, Pradeep Kumar Ramancharla}, TITLE = {Numerical Modeling of Buried Pipeline Crossing a Fault}, BOOKTITLE = {INTERNATIONAL CONFERENCES ON RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMIC}. YEAR = {2010}}

Pipelines are common transportation means for oil and natural gas, which act as an important lifeline facility for any nation. Often the design of these pipelines is a difficult task because they commonly are installed underground passing through different types of soil media. Many of these existing pipelines run through the faulted area, which continuously exposed to considerable risk of failure due to movement along the fault. In this paper, a numerical study is carried out to understand stress development in buried pipeline subjected to fault motion with Mundra-Delhi pipeline as a case study. For this purpose, a 3D finite element program is developed and the same is used to study stress development in the pipe subjected to fault motion. Also here study has been done to find out the effect of different soil media and effect of fault-pipeline angle for both strike slip and dip slip fault motion.

@inproceedings{bib_Dyna_2010, AUTHOR = {P.SUSHMA, Pradeep Kumar Ramancharla}, TITLE = {Dynamic soil structure interaction analysis of pile supported high rise structures}, BOOKTITLE = {INTERNATIONAL CONFERENCES ON RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMIC}. YEAR = {2010}}

Experiences from past earthquake disasters clearly shows that the ground motion was responsible for majority of property and life loss. Among the collapsed structures during the 1964 Niigata earthquake, the 1995 Kobe earthquake, the 1999 Koceli earthquake, the 2001 Bhuj earthquake and the 2004 Sumatra earthquake, excessive damage was occurred to pile supported bridges, towers, chimneys, high rise structures, etc. In view of this there is a need to study the complex behavior of soil-pile-structure interaction problems using numerical methods. In this research paper, a numerical study is carried out to understand the dynamic soil structure interaction of a high rise structure in a visco elastic half space in the presence of near by pile supported structures. The structure soil structure interaction is modelled by considering the direct methodology using a Finite element method based code ANSYS 10. Initially a two dimensional study is carried out for understanding the seismic response of group of high rise structures supported on pile foundations. The linear super structures are considered as framed structures of different dynamic characteristics suported on group of piles. Different case studies are made one in which the group effect of structures supported on piles are considered like group of two identical structures, group of three identical structures and group of three different structures, second one in which the effect of variability in structure height is considered like 5 storey structure, 10 storey structure and 15 storey structure and the third one in which the effect of variability in structure shape is considered. For each case the effect of structure …

@inproceedings{bib_Larg_2010, AUTHOR = {MOHD AHMED HUSSAIN, Pradeep Kumar Ramancharla}, TITLE = {Large Variation in PGA due to Presence of Heterogeneities in the Surface Soil}, BOOKTITLE = {INTERNATIONAL CONFERENCES ON RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMIC}. YEAR = {2010}}

In the proximity of an active fault, spatial variation of peak ground motion is significantly affected by the faulting mechanism. It has been observed that near fault ground motions consists of different characteristics compared to the far fault ground motions. Near fault records, in the distance range of less than 100 m from the faults are not available except for few cases. Therefore numerical simulation of ground motions for such near-fault situations is necessary. There is a need to enhance our understanding of the possible potential hazard that can be caused due to the future rupture activity by understanding the phenomenon of surface faulting. In this paper we propose numerical simulation based on discrete modeling to investigate the fault rupture propagation. Initially a two dimensional study is done for understanding the crack propagation due to various types of bedrock movement. A model of size 1000x150 m is selected for this purpose. It is observed as the stiffness of the media is decreasing, the affected surface is decreasing and also width of the shear crack zone is decreasing. However in the dynamic analysis we can observe the significant increase in amplification in soft media. Secondly, we attempted to study the presence of boulders. Surface faulting has been examined by keeping the boulder at different positions. We find that there is an increase in the shear zone as well as the PGA on the surface when the boulder is present on the foot wall. Finally, we performed the analysis using layered media and studied the affect of crack propagation and also the variation of peak accelerations Findings from the study can be utilized to assess the …

@inproceedings{bib_Eart_2010, AUTHOR = {Pradeep Kumar Ramancharla, Ajay Pratap Singh, Bal Krishna Rastogi , Santosh Kumar}, TITLE = {Earthquake Vulnerability Assessment of Existing Buildings in Gandhidham and Adipur Cities Kachchh, Gujarat (India)}, BOOKTITLE = {European Journal of Scientific Research}. YEAR = {2010}}

Bhuj earthquake of 26 January 2001 caused 14,000 casualties. Main reason for such huge casualties is low earthquake awareness and poor construction practices. Based on the technology advancement and knowledge gained after earthquake occurrences, the seismic code is usually revised. Last revision of IS 1893 (Criteria for earthquake resistant design of structures) was done in 2002 after a long gap of about 18 years. Some new clauses were included and some old provisions were updated. Assuming that concerned authorities will take enough steps for code compliance and the structures that are being constructed are earthquake resistant. In this light, what will happen to the safety of pre-code revision structures? These structures carry major percentage of vulnerable structure stock. Even if we have a very good disaster response system, it is impossible to reduce earthquake damage without considering the safety of pre-code revision structures. In this regard, a comprehensive study of seismic risk assessment of Gujarat is necessary. As a pilot study, government of Gujarat selected Gandhidham and Adipur cities. Rapid Visual Screening (RVS) was conducted on 16000 buildings in Gandhidham and Adipur cities. Initial results reveal that there are large variety of construction practices, however, predominantly RCC and masonry structure were found. RVS score of these structures reveal that in general buildings are of low quality and further evaluation and strengthening of buildings is recommended. Keywords: RVS, performance score, preliminary assessment and detailed assessment Earthquake Vulnerability Assessment of Existing Buildings in Gandhidham and Adipur Cities Kachchh, Gujarat (India)

@inproceedings{bib_DYNA_2010, AUTHOR = {GOPI RAM ADDALA, Neelima Satyam, Pradeep Kumar Ramancharla}, TITLE = {DYNAMIC ANALYSIS OF TRANSMISSION TOWERS UNDER STRONG GROUND MOTION}, BOOKTITLE = {International Earthquake Symposium}. YEAR = {2010}}

Transmission tower lines are one of most important life-line structures. It is necessary that these structures are designed for seismicity. The dynamic behavior of a single transmission tower and transmission tower system that are linked by conductors has been studied in this research work. The dynamic analysis is performed on both the single transmission tower and the tower line system. The wind force acting on the tower is considered as an equivalent static force. The seismic analysis of the tower has been performed in SAP2000 Nonlinear computer program (SAP2000, Computers and Structures). The tower elements are modeled using 3 D frame elements. The tower has been subjected to North-ridge strong ground motion (1994) and the Koyna strong ground motion (1967) to study the dynamic behavior as described in the present work. Parametric study has been carried out by studying the influence of cable on the tower when the force in the cable is applied at different angles to the cross arms. The non-linear material behavior of the leg members of the tower has been studied when it is subjected to the two strong ground motions considered. To understand the non-linear behavior of the material bi-linear model has been considered and it is analyzed in the present work.

@inproceedings{bib_Is_B_2010, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Is Bamboo A Favourite Construction Material for Civil Engineers?}, BOOKTITLE = {International Engineering and Construction Conference}. YEAR = {2010}}

Bamboo was used as construction material for housing since times immemorial. However, with the advent of materials like concrete and steel, its use has been signicantly reduced in last 50-100 years. On the other hand concrete and steel has large carbon footprints before even they are born. Use of wood has already banned by Central Public Works Department (CPWD). Similarly, State PWD's are also trying to follow the same. In this scenario, there is a great need to demonstrate cost eective housing with alternate technologies, especially like bamboo. However, for promoting bamboo as natural building material for housing, several dificulties are involved. This paper discusses the dificulties involved in promoting bamboo as sustainable construction material.

@inproceedings{bib_Can__2010, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Can Earthquakes be Predicted}, BOOKTITLE = {The Masterbuilder}. YEAR = {2010}}

Ask a common man about past earthquakes in india. Most people would answer Latur earthquake of 1993 and Bhuj earthquake of 2001 in addition to tsunami devastation of Dec 2004. However if we look at the figure we can see many events have occurred in last two decades. But why we remember only few events. The reason being obvious i.e life loss during these events. From the figure we can easily understand that during during last decades we have witnessed 6 moderate earthquake.

@inproceedings{bib_Effe_2010, AUTHOR = {MOHD AHMED HUSSAIN, Pradeep Kumar Ramancharla}, TITLE = {Effect of Heterogeneities in Soil on Spatial Variation of Peak Ground Acceleration}, BOOKTITLE = {Journal of Civil Engineering and Architecture,}. YEAR = {2010}}

In the proximity of an active fault, spatial variation of peak ground motion is significantly affected by the faulting mechanism. It has been observed that near fault ground motions consists of different characteristics compared to the far fault ground motions. Near fault records, in the distance range of less than 100 m from the faults are not available except for few cases. Therefore numerical simulation of ground motions for such near-fault situations is necessary. In addition to the understanding of the phenomenon of near fault ground motion there is a need to enhance our understanding of the possible potential hazard that can be caused due to the future rupture activity by understanding the phenomenon of surface faulting. In this paper we propose numerical simulation based on discrete modeling to investigate the fault rupture propagation and its effect on the surface peak ground acceleration. In the present two dimensional study rupture propagation due to bedrock motion has been observed for different shear wave velocity. A model of size 1000 X 150 m is selected for this purpose. It has been observed that as the stiffness of the media is decreasing, the affected surface is decreasing and also width of the shear crack zone is decreasing. Secondly, we attempted to study the ground motion on the surface due to the bedrock motion in presence of boulders in the soil media. Surface faulting has been examined by keeping the boulder at different positions. We find that there is an increase in the shear zone as well as the PGA on the surface when the boulder is present on the foot wall and in the vicinity of the rupture zone. Finally, we performed the …

@inproceedings{bib_Prel_2010, AUTHOR = {Rajaram Chenna, BODIGE NARENDER, Neelima Satyam, Pradeep Kumar Ramancharla}, TITLE = {Preliminary Seismic Hazard Map of Peninsular India}, BOOKTITLE = {Symposium on Earthquake Engineering & Golden Jubilee celebrations}. YEAR = {2010}}

This paper presents the preliminary seismic hazard assessment of the peninsular India (lat. 10-26N and long. 68-90E) which is considered to be seismically most stable land masses of the Indian plate. Past major seismic events in this region (Koyna, 10 Dec 1967; Bhadrachalam, 13 Apr 1969; Hyderabad, 30 Jun 1983; Latur, 30 Sep 1993; Jabalpur, 22 May 1997; Bhuj, 26 Jan 2001) clearly shows that the seismicity of the area is highly varying. There were five damaging earthquakes with magnitudes Mw 6.0 occurred in this region, stressing the importance of detailed seismic hazard assessment for this region. For India, Bhatia published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the detailed seismicity, tectonic and geologic characteristics. Around 110 major faults are considered in this present research study for estimating the peak ground acceleration at the bedrock level using the attenuation relationships developed by Atkinson and Boore. The considered area under peninsular region has been divided into grid pattern with 10x10 and around 280 site specific locations are considered for the detailed analysis. From this study, it is observed that 30% of PI is overestimated and 12% is underestimated when compared with PGA values for various regions provided in Indian seismic code IS: 1893-2002. The results show that there is a great need for carrying out the detailed microzonation of an area within the peninsular India.

@inproceedings{bib_Exti_2010, AUTHOR = {Vaibhav Jain, Pradeep Kumar Ramancharla}, TITLE = {Extinction of vernacular architecture in India Are we heading in right direction?}, BOOKTITLE = {World Congress on Disaster Management}. YEAR = {2010}}

Heritage could be something which is acquired from one’s ancestors. It could be natural heritage, cultural heritage, food heritage, built monumental heritage; or it could be the virtue of vernacular architectural & construction techniques which people from many different communities have secured from their ancestors through generations. But, with the advent of modernism, vernacular architecture, construction techniques and skills are fast disappearing as there is simply no demand for them anymore. Similar to the case with many of our traditional crafts, we are facing the risk of extinction of skills for buildings. As more and more constructions in villages are turning towards cement and steel, the traditional and sophisticated art of construction will fade away sooner rather than later. The preservation of such skills and, in fact their propagation must be an important priority for stakeholders and policy makers. This paper not only the presents the risks of extinction which these heritage construction techniques & skills are facing from modern mind-set, but it also presents some of the vernacular building typologies in seismic zones IV & V showing, their uniqueness in intertwining the culture and resistance to natural forces of the region.

@inproceedings{bib_NUME_2009, AUTHOR = {Pradeep Kumar Ramancharla, Kimiro Meguro}, TITLE = {NUMERICAL MODELING OF INFINITE MEDIA USING APPLIED ELEMENT METHOD}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2009}}

In this paper, we discuss the numerical modeling of infinite media using transmitting boundary condition. This is done for simulating the propagation of elastic waves in soil media. Wave interaction with different kinds of boundaries is discussed explaining the numerical modeling procedure. Wave propagation in different directions is studied while calculating the velocities in different soil domain. For investigating the above-mentioned objectives, we used newly developed numerical model, viz., Applied Element Method and compared our results with Finite Element Method (FEM).

@inproceedings{bib_Scho_2009, AUTHOR = {Raju Sangam, TERALA SRIKANTH , Pradeep Kumar Ramancharla}, TITLE = {School Awareness Programme On Earthquake Disasters and Preparedness}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2009}}

Earthquake problems in India need no introduction. Some of the great earthquakes of the world occurred in India and neighborhood areas. During past two decades, India has witnessed 7 moderate earthquakes which caused large number of casualties and innumerable property loss. Most of these losses are due to poor quality of construction and generally low level of awareness of the earthquake hazard prevalent in the country. In this regard, there is a need for coordinated and sustained effort towards earthquake risk reduction in the country. This can be achieved through education and awareness building.

@inproceedings{bib_NUME_2009, AUTHOR = {CHAUDHARI VASUDEO GOVIND, Pradeep Kumar Ramancharla}, TITLE = {NUMERICAL MODELLING OF BURIED PIPELINE CROSSING A FAULT}, BOOKTITLE = {INTERNATIONAL CONFERENCES ON RECENT ADVANCES IN GEOTECHNICAL EARTHQUAKE ENGINEERING AND SOIL DYNAMIC}. YEAR = {2009}}

Pipelines are common transportation means for oil and natural gas, which act as an important lifeline facility for any nation. Often the design of these pipelines is a difficult task because they commonly are installed underground passing through different types of soil media. Many of these existing pipelines run through the faulted area, which continuously exposed to considerable risk of failure due to movement along the fault. Installation and maintenance costs of these pipelines directly depend on the total length of the pipelines. Furthermore ideal alignment for any pipeline as a straight line between the source and destination point is not that easy in the area where fault are present. It becomes necessary to divert the alignment about fault line which increases the length and subsequently operational and installation costs of pipeline. Common problems seen in the pipeline crossing the fault are change of alignment due to movement along the fault.

@inproceedings{bib_A_St_2009, AUTHOR = {Neelima Satyam, RANJEET JOSHI, Pradeep Kumar Ramancharla}, TITLE = {A Study on Earthquake Hazard Assessment in Peninsular India}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2009}}

This paper presents the detailed seismic hazard assessment of the peninsular India (lat. 8-28N and long. 67.5-90E) which is considered to be seismically most stable landmasses of the Indian plate. Past seismic history in this region (Koyna, 10 December 1967; Bhadrachalam, 13 April 1969; Broach, 23 March 1970; Hyderabad, 30 June 1983; Latur, 30 September 1993; Jabalpur, 22 May 1997; Bhuj, 26 January 2001 etc) clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitudes greater than Mw 6.0 have occurred in this region, stressing the importance of detailed seismic hazard assessment for the region. For India, Bhatia et al. (1999) published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the seismicity, tectonic and geological characteristics and using the collected earthquake data Peak Ground Acceleration was estimated using the attenuation relation developed by Iyengar and Raghukanth (2004). Estimated PGA values were used to compute the deviation with respect to assigned PGA values for various regions provided in Indian Standard code IS 1893:2002. The results show that, the estimated PGA in many areas of the Peninsular India is more than the specified value in the current seismic macrozonation map of the country. This provides an important basis for attempting the detailed microzonation of an area within the Penisular India. Key words: Seismic hazard, Peak ground acceleration (PGA), Peninsular India, Seismiczonation

@inproceedings{bib_Eart_2009, AUTHOR = {Neelima Satyam, Pradeep Kumar Ramancharla, Madhav, M R}, TITLE = {Earthquake Hazard in Peninsular India,}, BOOKTITLE = {Journal of Seismology}. YEAR = {2009}}

This paper present detailed seismic hazard assessment of the peninsular india which is considered to be seismically most stable landmasses of the indian plate. Past seismic history in this region clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitude greater than 6 have occurred in this region stressing the importance of detailed seismic hazard assessment for the region.

@inproceedings{bib_Eart_2009, AUTHOR = {Neelima Satyam, Pradeep Kumar Ramancharla, Madhav, M R}, TITLE = {Earthquake Hazard Assessment of Peninsular India}, BOOKTITLE = {Geo-Informatics and Hazard Mapping Symposium,}. YEAR = {2009}}

This paper presents the detailed seismic hazard assessment of the peninsular India (lat. 8°-28°N and long. 67.5°-90°E) which is considered to be seismically most stable landmasses of the Indian plate. Past seismic history in this region (Koyna, 10 December 1967; Bhadrachalam, 13 April 1969; Broach, 23 March 1970; Hyderabad, 30 June 1983; Latur, 30 September 1993; Jabalpur, 22 May 1997; Bhuj, 26 January 2001 etc) clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitudes greater than Mw 6.0 have occurred in this region, stressing the importance of detailed seismic hazard assessment for the region. For India, Bhatia et al. (1999) published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the seismicity, tectonic and geological characteristics and using the collected earthquake data Peak Ground Acceleration was estimated using the attenuation relation developed by Iyengar and Raghukanth (2004). Estimated PGA values were used to compute the deviation with respect to assigned PGA values for various regions provided in Indian Standard code IS 1893:2002. The results show that, the estimated PGA in many areas of the Peninsular India is more than the specified value in the current seismic macrozonation map of the country. This provides an important basis for attempting the detailed microzonation of an area within the Penisular India.

@inproceedings{bib_DAMA_2009, AUTHOR = {VRUSHALI KAMALAKAR, Pradeep Kumar Ramancharla}, TITLE = {DAMAGE BASED LIFE OF HISTORICAL CONSTRUCTIONS IN SEISMIC ENVIRONMENT}, BOOKTITLE = {European Journal of Scientific Research}. YEAR = {2009}}

Indian Subcontinent is one of the seismically active regions of the world. The seismicity of India can be divided into 4 groups: Himalayan Region, Indo-Gangetic Plain, Kutch-Kathiawar Region and the Peninsular India (Ref EU Report 2003). Himalayas are one of the rare sites of continent to continent collision and also tectonically very active belt. The high seismicity of the region can be observed from the past events occurred in the region as shown in Figure.1. Depending on the past earthquakes, Bureau of Indian Standards has prepared the Seismic Zonation map of India (IS-1893-2002), which divides the country into 4 different zones. As per the zonation map 57% land of the country falls under high seismic zone. These maps do not consider the frequency of occurrence of earthquakes; hence they do not divide the country into regions of equal hazard and risk. For cultural heritage and other important structures, these maps act only as a guideline for the expected intensities. For those structures, site specific seismic hazard maps have to be generated specially for use. Rigorous quantifications of seismic hazard in detail for the Delhi region have not been carried out so far. Chouhan (Proc.INSA) estimated the focal depth of earthquake around Delhi to be about 8 km. His frequency-magnitude analyses lead to the conclusion that the maximum size of an earthquake that may occur in this region would be 7.6. The work of Srivastav and Roy (1982) indicates that in a period of 50 years a magnitude 6 earthquakes are almost certain and that there is 80% probability of a 7 magnitude event visiting the region. Khattri (1992) has carried out an exercise estimating the seismic hazard for the northern region of the country. According to this study in a fifty year window of 1983 - 2033, the peak ground accelerations around Delhi would be 0.2 g with 10% probability of exceedence. Delhi and its environs have not yet experienced this level of ground vibration in the above time period. Even if these estimates need further refinement they indicate the nature of events expected for Delhi city (Iyengar, 2000). Keeping in view all these studies, the effect of any future earthquake in Delhi region is studied in this paper.

@inproceedings{bib_A_No_2009, AUTHOR = {Neelima Satyam, Rajeet Joshi, Pradeep Kumar Ramancharla}, TITLE = {A Note on the accuracy of seismic hazard in Peninsular India}, BOOKTITLE = {International Journal of Earth Sciences and Engineering}. YEAR = {2009}}

This paper presents the detailed seismic hazard assessment of the peninsular India (lat. 8°-28°N and long. 67.5°-90°E) which is considered to be seismically most stable landmasses of the Indian plate. Past seismic history in this region (Koyna, 10 December 1967; Bhadrachalam, 13 April 1969; Broach, 23 March 1970; Hyderabad, 30 June 1983; Latur, 30 September 1993; Jabalpur, 22 May 1997; Bhuj, 26 January 2001 etc) clearly shows that the seismicity of the area is varying. There were more than five damaging earthquakes with magnitudes greater than Mw 6.0 have occurred in this region, stressing the importance of detailed seismic hazard assessment for the region. For India, Bhatia et al. (1999) published a probabilistic seismic hazard map based on several well identified and prominent source zones in the country. An attempt has been made in this paper to study the present seismic status of this region incorporating the seismicity, tectonic and geological characteristics and using the collected earthquake data Peak Ground Acceleration was estimated using the attenuation relation developed by Iyengar and Raghukanth (2004). Estimated PGA values were used to compute the deviation with respect to assigned PGA values for various regions provided in Indian Standard code IS 1893:2002. The results show that, the estimated PGA in many areas of the Peninsular India is more than the specified value in the current seismic macrozonation map of the country. This provides an important basis for attempting the detailed microzonation of an area within the Penisular India

@inproceedings{bib_A_No_2008, AUTHOR = {RANJEET JOSHI, Pradeep Kumar Ramancharla}, TITLE = {A Note On The Accuracy of Seismic Hazard in Peninsular India}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2008}}

The study was conducted in order to compute the deviations in the Peak Ground Acceleration values as specified in the IS 1893 2002 for different regions from the values obtained from modern empirical attenuation formulae. For this purpose earthquake events catalogue was prepared for various earthquake that occurred from year 1984 to 2003 in peninsular India.

@inproceedings{bib_Opti_2007, AUTHOR = {VENKATA DILIP KUMAR P, Pradeep Kumar Ramancharla}, TITLE = {Optimum Evacuation in Public Gathering Places During the Time of Disaster}, BOOKTITLE = {nternational Symposium on Automation and Robotics in Construction}. YEAR = {2007}}

Urbanization is rapidly increasing all over the world. Past two decades in India many cities have attracted large population. Reasons being the belief of better education health care job/business prospects etc. For meeting the demands of population density many high-rise structures and large public gathering places are emerging in cities. Places where few thousands of people can meet are quite common in major cities. It is due to this reason evacuation at the public gathering places has gained a lot of importance

@inproceedings{bib_Esti_2007, AUTHOR = {Pradeep Kumar Ramancharla, Ranjeet Joshi, MD. Ziya Ur Rahman Siddiqui}, TITLE = {Estimation of Risk Due to Earthquake Hazard in AP India an IT Based Approach}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2007}}

This paper describes the procedure of vulnerability assessment for building structures in AP India. The objective of this paper is to define the building classification and development of damage probability matrix using fragility curve parameters of the building structures in Andhra Pradesh by using the avaiable information in Vulnerability Atlas of India developed by Building Materials and Technology promotion council Govt. of India (BMTPC).

@inproceedings{bib_Use__2007, AUTHOR = {RANJEET JOSHI, Pradeep Kumar Ramancharla, Maluram Omprakash Sharma}, TITLE = {Use of Web Technologies for Raising Awareness About Seismic Risk}, BOOKTITLE = {nternational Symposium on Automation and Robotics in Construction}. YEAR = {2007}}

Earthquake Problems are not new to the country. We have witnessed several moderate earthquakes in the last two decades causing innumerable property loss and life loss. In order to minimize the loasses. We need to raise the awareness about earthquake resistant design of structures. This can be achieved by spreading the information on hazard vulnerability and risk to concerend people.

@inproceedings{bib_ESTI_2007, AUTHOR = {MD. Ziya Ur Rahman Siddiqui, RANJEET JOSHI, Pradeep Kumar Ramancharla}, TITLE = {ESTIMATION OF EARTHQUAKE VULNERABILITY OF A STRUCTRUE}, BOOKTITLE = {International Conference on Natural Hazards and Disaster Management}. YEAR = {2007}}

This paper describes the procedure of vulnerability assessment of structures for site specific peak ground acceleration. The objective of this paper is to define the building classification and development of damage probability matrix which represent the vulnerability of structure. The organization of this paper is as follows. First, the types of the structures are reviewed and a classification of structure based on the available data with Vulnerability Atlas of India is done. Second, the description of methodologies developed under various organizations is studied, adopted and summarized. Third, the theoretical methodology of the vulnerability analysis using fragility curve parameters given by HAZUS and capacity curve generated using SAP2000 for typical structure are presented and performance of structure is calculated by using capacity spectrum method.

@inproceedings{bib_DYNA_2006, AUTHOR = {Pradeep Kumar Ramancharla, Hatem Tagel Din, Kimiro Meguro}, TITLE = {DYNAMIC MODELING OF DIP-SLIP FAULTS FOR STUDYING GROUND SURFACE DEFORMATION USING APPLIED ELEMENT METHOD}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2006}}

When an active bedrock fault ruptures, the movement along the fault propagates through the overlying soil and produces zones of intense shear. If the fault movement propagates upto or near the ground surface, the damage to constructed facilities due to faulting, in conjunction with that induced by strong ground motion, can be significant. This paper contributes to the understanding of the response of soil deposits to the underlying bedrock fault displacement. In the conventional attenuation relationship, peak ground acceleration shows maximum value at the closest distance from the fault. However, in the real observations, sometimes it is found that the damage near to the surface fault is not maximum, instead it is high little away from the surface rupture zone. To understand the above-mentioned response of soil deposits, we attempted to develop a new application to Applied Element Method (AEM) by modeling the fault rupture zone. In this, we study the behavior of dip-slip faults. The effect of the slip velocity on the ground motion is studied first and then the attenuation of PGA in the near fault zone is studied. Effect of the material properties is also discussed.

@inproceedings{bib_Are__2006, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Are we ready to face another earthquake}, BOOKTITLE = {The Masterbuilde}. YEAR = {2006}}

Earthquake, now everyone is familiar with this word. We have clearly witnessed during the recent Sumatra, Indonesia earthquake (M 9.0) the amount of damage an earthquake can cause to the society. Had this earthquake occurred on land, it would have easily damaged few hundreds of kilometers and the damage estimates would have been unimaginable. Earthquakes are not new to our country. We have had the long history of earthquake occurrences. Some of the major earthquakes of the world occurred in our country and neighborhood areas. During past 15 years also we have witnessed 6 moderate earthquakes: Bihar-Nepal border (M6.4) in 1988, Uttarkashi, Uttaranchal (M6.6) in 1991, Latur, Maharastra (M6.3) in 1993, Jabalpur, Madhya Pradesh (M6.0) in 1997, Chamoli, Uttaranchal (M6.8) in 1999 and Bhuj, Gujarat (M6.9) in 20011). These earthquakes caused around 40,000 casualties (see Table 1) and innumerable property loss. These events occurred with a time gap of 2 ~ 3 years. Are we ready to face another event? Even with the current level of understanding, it is very difficult to predict the occurrence time and exact location of next earthquake. The only way to ensure the safety is to get prepared.

@inproceedings{bib_Inte_2006, AUTHOR = {Pradeep Kumar Ramancharla, ASHUTOSH KUMAR SINGH, B RAJESH BABU}, TITLE = {Interactive Structural Dynamics Learning Kit}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2006}}

Natural disasters like earthquake, landslide, flood, drought, cyclone, forest fire, volcanic eruption are quite common in different parts of the globe. These natural disasters lead to the loss of life, property damage and socio-economic disruption. Earthquakes are one of the worst among the natural disasters. Seismic zonation map given in IS 1893:2002 shows that India is highly vulnerable for earthquake and over 60% of India is prone to moderate to major earthquakes. During past century, India has witnessed more than 650 earthquakes of magnitude greater than 5 and during past 15 years, 6 earthquakes of magnitude over 6. From recent earthquakes, it is very well understood that lack of awareness is one of the contributing factors for huge casualty losses. In order to increase the awareness about the effects of earthquakes among professionals involved in construction, it is necessary to make them understand the concepts of structural dynamics and earthquake engineering. For this, we have developed a software tool called Interactive Structural Dynamics Learning Kit (ISDLK) for explaining structural dynamics in a simple manner. For convenience in explaining the concepts, we divided the tool into six modules. Each module contains few experiments with good G.U.I. In these modules, user can input the value and he/she can find the desired results with explanation using graphical diagram. At the end of sixth module, user can understand the complete dynamic behavior of a structure. ISDLK aims to help students, architects and design professional in understanding structural dynamics.

@inproceedings{bib_Role_2006, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Role of Information Technology in Earthquake Disaster Mitigation}, BOOKTITLE = {The Masterbuilde}. YEAR = {2006}}

India has witnessed 6 earthquakes during past 15 years causing around 40,000 casualties and immense property loss. More than 90% of these casualties are due to collapse of buildings and they occurred within very short period of time after the earthquake. Hence, for reducing casualty losses and subsequent consequences due to earthquake, it is very important to study the response of structures due to seismic excitations. For studying the response of the structures and consequent issues after the earthquake disaster, information technology can play a major role. This paper contributes to understand the importance of information technology in earthquake disaster mitigation.

@inproceedings{bib_Role_2006, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Role of Concrete Constructions in Earthquake Disaster Mitigation}, BOOKTITLE = {National Conference on Emerging Trends in Concrete Constructions}. YEAR = {2006}}

India has witnessed 6 earthquakes during past 15 years causing around 40,000 casualties and immense property loss. More than 90% of these casualties are due to collapse of buildings and they occurred within very short period of time after the earthquake. Hence, for reducing casualty losses and subsequent consequences due to earthquake, it is very important to study the response of structures due to seismic excitations. This paper contributes to understand the importance of concrete constructions in earthquake disaster mitigation. Paper first discusses the effects of earthquakes of past in general and gives a brief summary of 26th Jan, Bhuj earthquake. Shortcomings observed in constructions during authors visit to Bhuj are highlighted. Finally the recommendations for concrete constructions are given.

@inproceedings{bib_3D_N_2006, AUTHOR = {Pradeep Kumar Ramancharla, Kimiro Meguro}, TITLE = {3D Numerical modeling of Faults for Studying Ground Surface Deformation Using Applied Element Method}, BOOKTITLE = {Current Science}. YEAR = {2006}}

This article aims to understandthe response of soil deposits underlying bedrock fault displacement in three dimensions. When an active bedrock fault ruptures movement along the fault propagates through the overlying soil and produces zones of intense shear. Hence it is important to study the sruface behaviour based on fault characteristics. Hence we attempted to develop application of applied element method by modelling the fault rupure zone. In this article we have modelled the fault rupture problem in three dimensions. First a simple model is used to illustrate absorption of the bedrock deformation by the overlying soin in elastic case. In the later part nonlinear analysis is carried out to study the complex failure propogation in three dimensions. Influence of mechanical propertices of the material is also discussed.

@inproceedings{bib_Desi_2006, AUTHOR = {Sandip DAS, Vinay K. GUPTA, Pradeep Kumar Ramancharla}, TITLE = {Design Fore Ratio Specturm for Performance Based Design in Case of Multiple Events}, BOOKTITLE = {Europen Conference on Earthquake Engineering and Seismology}. YEAR = {2006}}

The earthquake-resistant design methodology in most existing codes of practice is based on ensuring no collapse” during the most severe event expected at the given site while most of the input energy is dissipated through inelastic deformations. Evolution of the performance-based design over the last decade has seen a few performance levels added up to this so that the structure remains functional even after a moderately strong event. This methodology however overlooks the possibility that in case of multiple earthquake events expected during the design life of the structure the structure may get gradually damaged and that it may not be feasible to carry out repairs in the structure after every damaging event. As a result, the structure may collapse earlier than expected and perhaps during an event of moderate intensity. To address such a concern a new spectrum, called as design force ratio spectrum is proposed in this paper. DFR spectrum gives the ratio by which the design yield force level of a conventionally-designed single degree of freedom structure should be raised such that the damage caused by all earthquake events expected to occur during its lifetime is limited to a specified level. A numerical study is carried out for a hypothetical seismic region by following a simple procedure based on several assumptions and DFR spectra are obtained for elastic-perfectly plastic oscillators when the return periods of earthquakes follow exponential distribution over the entire range of magnitudes.

@inproceedings{bib_Eart_2006, AUTHOR = {RANJEET JOSHI, Pradeep Kumar Ramancharla}, TITLE = {Earthquake Vulnerability Assessment of Urban Areas in India An IT Based Approach}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2006}}

India shares over 16% of world population with only 3.4% of landmass. This has resulted in the dispersion of population to disaster prone regions. Therefore even moderate earthquakes are resulting in high damage estimates. Growing opportunities, better health care and good education is holding a significant population in Indian meg a cities but almost all of these cities lie in Seismic zone III or above which is having the possibility of earthquakes up to intensity VII or more. All these factors necessitate an effective Disaster Management System in India.

@inproceedings{bib_Nonl_2006, AUTHOR = {Pradeep Kumar Ramancharla, Kimiro Meguro }, TITLE = {Nonlinear Numerical Modeling of Infinite Media Using Applied Element Method}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2006}}

It is very well recognized that structure which is stiff interacts dynamically with soil during earthquakes. In order to carry out the investigation in dynamic way, the main problem that will arise in modeling is unbounded nature of soil medium. The real field is not surrounded by any boundary and any numerical model that we study have to be defined by using a proper boundary that takes care of radiation of dynamic energy into unbounded soil. Conventional boundaries used for studying the structural analysis may not give proper results for qualitative discussion. So, we need to model the soil similar to actual field conditions. For that we need to model an absorbing boundary condition.

@inproceedings{bib_What_2006, AUTHOR = {N Purnachandra Rao, Pradeep Kumar Ramancharla}, TITLE = {What Caused the Great Tsunamigenic Earthquake of 26 December 2004}, BOOKTITLE = {Asia Oceania Geosciences Society Suntec Singapore}. YEAR = {2006}}

On 26 December 2004 a devastating earthquake of magnitude 9.3 occurred in Sumatra region of Indonesia. This earthquake produced the world’s deadliest tsunami in the Indian Ocean region that claimed more than 300, 000 lives. This earthquake was quickly followed by another great one of magnitude 8.7 on 28 March 2005 in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession.

@inproceedings{bib_Plat_2006, AUTHOR = {N. Purnachandra Rao, A. Hanmantha Chary, Pradeep Kumar Ramancharla}, TITLE = {Plate Junctions and Great Earthquakes The Recent Sumantran Puzzle}, BOOKTITLE = {European Geosciences Union General Assembly}. YEAR = {2006}}

The great devastating tsunamigenic earthquake of 26 December 2004 in sumatra was quickly followed by another great one on 28 march 2005 in the same region. This is for the first time in the known histroy of seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates in in generation of such great earthquakes.

@inproceedings{bib_3D_N_2006, AUTHOR = {Pradeep Kumar Ramancharla, Kimiro Meguro}, TITLE = {3D Numerical modelling of faults for study of ground surface deformation using applied element method}, BOOKTITLE = {Current Science}. YEAR = {2006}}

This article aims to understand the response of soil deposits underlying bedrock fault displacement in three dimensions. When an active bedrock fault ruptures, movement along the fault propagates through the overlying soil and produces zones of intense shear. Hence, it is important to study the surface behaviour based on fault characteristics. Hence we attempted to develop application of Ap- plied Element Method by modelling the fault rupture zone. In this article, we have modelled the fault rupture problem in three dimensions. First, a simple model is used to illustrate absorption of the bedrock deformation by the overlying soil in elastic case. In the later part, nonlinear analysis is car- ried out to study the complex failure propagation in three dimensions. Influence of mechanical properties of the material is also discussed.

@inproceedings{bib_Caus_2006, AUTHOR = {N Purnachandra Rao, Pradeep Kumar Ramancharla}, TITLE = {Causative mechanism of the Great Tsunamigenic Sumatran Earthquake of 26 December 2004 through Modeling of Stress Field at Plate Junctions}, BOOKTITLE = {Hannover}. YEAR = {2006}}

The great devastating tsunamigenic earthquake of 26 December 2004 (M9.0) in Sumatra was quickly followed by another great one on 28 March 2005 (M8.7) in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates, in generation of such great earthquakes. The 26 December 2004 and the 28 March 2005 earthquakes in the Andaman-Sumatra arc seem to have occurred on distinct India-Burma and Australia-Sunda mega-thrust segments possibly separated by a stress barrier or a lithospheric break at the junction that prevented stress transfer along the arc during both earthquakes. This is evidenced by the confinement of aftershock activity on either sides of the barrier during each of the earthquakes. It appears that the large impulsive co-seismic deformation during the first earthquake of 26 December 2004 triggered the already saturated adjoining segment of the Australia-Sunda plate boundary within a short period of 3 months, generating the second one on 28 March 2005. An examination of the locations of the world’s 12 largest earthquakes since the year 1900 indicates a strong correlation (>80%) with multiple plate junctions. Apart from the 2 great Sumatran earthquakes observed at the quadruple plate junction of India, Burma, Australia and Sunda, even the 2 greatest earthquakes in the Himalayas – the 1897 Shillong and the 1950 Assam earthquakes – each of magnitude 8.7, occurred at a quadruple junction near the eastern Himalayan syntaxis, comprising the India, Eurasia, Burma and Sunda plates. Finite element modeling of stress field at plate junctions indicates the mechanism of great stress build-up due to the plate geometry and variable plate velocities. In general, it is inferred that triple and quadruple plate junctions are potential targets for future great earthquakes.

@inproceedings{bib_Mode_2006, AUTHOR = {N. Purnachandra Rao, Pradeep Kumar Ramancharla}, TITLE = {Modeling the Stress Field at Plate Junctions : A new mechanism for the Great Tsunamigenic Sumatran Earthquake of 26 December 2004}, BOOKTITLE = {Workshop on Tsunami and Modeling}. YEAR = {2006}}

The great devastating tsunamigenic earthquake of 26 December 2004 (M9.0) in Sumatra was quickly followed by another great one on 28 March 2005 (M8.7) in the same region. This is for the first time in the known history of Seismology that 2 great earthquakes have occurred in close spatial proximity in such a quick succession. In the present study we highlight the role of the multiple plate junction comprising the India, Burma, Australia and Sunda plates, in generation of such great earthquakes. The 26 December 2004 and the 28 March 2005 earthquakes in the Andaman-Sumatra arc seem to have occurred on distinct India-Burma and Australia-Sunda mega-thrust segments possibly separated by a stress barrier or a lithospheric break at the junction that prevented stress transfer along the arc during both earthquakes. This is evidenced by the confinement of aftershock activity on either sides of the barrier during each of the earthquakes. It appears that the large impulsive co-seismic deformation during the first earthquake of 26 December 2004 triggered the already saturated adjoining segment of the Australia-Sunda plate boundary within a short period of 3 months, generating the second one on 28 March 2005. An examination of the locations of the world’s 12 largest earthquakes since the year 1900 indicates a strong correlation (>80%) w

@inproceedings{bib_ROLE_2005, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {ROLE OF INFORMATION TECHNOLOGY IN EARTHQUAKE DISASTER MITIGATION}, BOOKTITLE = {The Masterbuilde}. YEAR = {2005}}

India has witnessed 6 earthquakes during past 15 years causing around 40,000 casualties and immense property loss. More than 90% of these casualties are due to collapse of buildings and they occurred within very short period of time after the earthquake. Hence, for reducing casualty losses and subsequent consequences due to earthquake, it is very important to study the response of structures due to seismic excitations. For studying the response of the structures and consequent issues after the earthquake disaster, information technology can play a major role. This paper contributes to understand the importance of information technology in earthquake disaster mitigation

@inproceedings{bib_Are__2005, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Are we ready to face another earthquake?}, BOOKTITLE = {The Masterbuilde}. YEAR = {2005}}

Earthquake, now everyone is familiar with this word. We have clearly witnessed during the recent Sumatra, Indonesia earthquake (M 9.0) the amount of damage an earthquake can cause to the society. Had this earthquake occurred on land, it would have easily damaged few hundreds of kilometers and the damage estimates would have been unimaginable. Earthquakes are not new to our country. We have had the long history of earthquake occurrences. Some of the major earthquakes of the world occurred in our country and neighborhood areas. During past 15 years also we have witnessed 6 moderate earthquakes: Bihar-Nepal border (M6.4) in 1988, Uttarkashi, Uttaranchal (M6.6) in 1991, Latur, Maharastra (M6.3) in 1993, Jabalpur, Madhya Pradesh (M6.0) in 1997, Chamoli, Uttaranchal (M6.8) in 1999 and Bhuj, Gujarat (M6.9) in 20011). These earthquakes caused around 40,000 casualties (see Table 1) and innumerable property loss. These events occurred with a time gap of 2 ~ 3 years. Are we ready to face another event?

@inproceedings{bib_SOFT_2005, AUTHOR = {ASHUTOSH KUMAR, B RAJESH BABU, Pradeep Kumar Ramancharla}, TITLE = {SOFTWARE TOOL FOR UNDERSTANDING CONCEPTS OF STRUCTURAL DYNAMICS AND EARTHQUAKE ENGINEERING}, BOOKTITLE = {National Conference on Recent Trends in Civil and Mechanical Engineering}. YEAR = {2005}}

Natural disasters like earthquake, landslide, flood, drought, cyclone, forest fire, volcanic eruption are quite common in different parts of the globe. These natural disasters lead to the loss of life, property damage and socio-economic disruption. Earthquakes are one of the worst among the natural disasters. Seismic zonation map given in IS 1893:2002 shows that India is highly vulnerable for earthquake and over 60% of India is prone to moderate to major earthquakes. During past century, India has witnessed more than 650 earthquakes of magnitude greater than 5 and during past 15 years, 6 earthquakes of magnitude over 6. From recent earthquakes, it is very well understood that lack of awareness is one of the contributing factors for huge casualty losses. In order to increase the awareness about the effects of earthquakes among professionals involved in construction, it is necessary to make them understand the concepts of structural dynamics and earthquake engineering. For this, we have developed a software tool called “Interactive Structural Dynamics Learning Kit (ISDLK)” for explaining structural dynamics in a simple manner. For convenience in explaining the concepts, we divided the tool into six modules. Each module contains few experiments with good G.U.I. In these modules, user can input the value and he/she can find the desired results with explanation using graphical diagram. At the end of sixth module, user can understand the complete dynamic behavior of a structure. ISDLK aims to help students, architects and design professional in understanding structural dynamics.

@inproceedings{bib_VIRT_2005, AUTHOR = {ASHUTOSH KUMAR, B RAJESH BABU, Pradeep Kumar Ramancharla}, TITLE = {VIRTUAL STRUCTUAL DYNAMICS LABORATORY}, BOOKTITLE = {National Seminar on Sustainable Technologies in Civil & Mechanical Engineering}. YEAR = {2005}}

Earthquake problems in India need no introduction. From recent earthquakes, it is very well understood that lack of awareness is one of the contributing factors for huge casualty losses. In order to increase the awareness about the effects of earthquakes among professionals involved in construction, it is necessary to make them understand the concepts of structural dynamics and earthquake engineering. To address this issue, we have developed a software tool named Virtual Structural Dynamics Laboratory. Using this tool, a person with some knowledge of structural engineering can be able to learn by himself the fundamentals of structural dynamics. For convenience in explaining the concepts, we divided this tool into four modules. Each module contains few experiments with good G.U.I. In these experiments, user can find the explanation with graphical diagram. At the end of fourth module user can understand the dynamic behavior of the structure. This software tool aims to help students, architects and civil engineers in understanding the principles of structural dynamics.

@inproceedings{bib_Dyna_2004, AUTHOR = {Pradeep Kumar Ramancharla, Tagel-Din HATEM, Kimiro MEGURO}, TITLE = {Dynamic modeling of dip-slip faults for studying ground surface deformation using applied element method}, BOOKTITLE = {World Conference on Earthquake}. YEAR = {2004}}

When an active bedrock fault ruptures, the movement along the fault propagates through the overlying soil and produces zones of intense shear. If the fault movement propagates upto or near the ground surface, the damage to constructed facilities due to faulting, in conjunction with that induced by strong ground motion, can be significant. This paper contributes to the understanding of the response of soil deposits to the underlying bedrock fault displacement. In the conventional attenuation relationship, peak ground acceleration shows maximum value at the closest distance from the fault. However, in the real observations, sometimes it is found that the damage near to the surface fault is not maximum, instead it is high little away from the surface rupture zone. To understand the above-mentioned response of soil deposits, we attempted to develop a new application to Applied Element Method (AEM) by modeling the fault rupture zone. In this, we study the behavior of dip-slip faults. The effect of the slip velocity on the ground motion is studied first and then the attenuation of PGA in the near fault zone is studied. Effect of the material properties is also discussed.

@inproceedings{bib_Equi_2004, AUTHOR = {K B S SUNIL BABU, Pradeep Kumar Ramancharla}, TITLE = {Equivalent Static Analysis as per IS 1893:2002: A Simple Software Tool}, BOOKTITLE = {New Technologies for Urban Safety of Mega Cities in Asia}. YEAR = {2004}}

This paper presents a software tool for performing the static and dynamic analysis of regular and simple multi-storied structures. This analysis procedure is based on IS 1893:2002 (Part I), Criteria for Earthquake Resistant Design of Structures. This tool is a windows based software program developed in Visual Basic. The tool provides a userfriendly GUI for the calculation of base shear and its distribution over the height of the structure, depending on the input parameters. Usual input parameters are structural dimensions, type of structure, soil type, purpose of structure and location. Though this tool is simple, can be used for verification of design within short time. This tool is aimed to help students, architects and engineers during design of earthquake resistant structures.

@inproceedings{bib_Dyna_2003, AUTHOR = {Pradeep Kumar Ramancharla}, TITLE = {Dynamic Simulation of Base Fault Motion for Studying Ground Surface Deformation Motion}, BOOKTITLE = {USJapanWorkshop on Earthquake Resistant Design of Lifeline Facilities and Countermeasures Against Li}. YEAR = {2003}}