Along with being one of the most populated regions of the world, Indonesia has one of the highest natural disaster rates worldwide. One such natural disaster that Indonesia is particularly prone to are tsunamis. Tsunamis are primarily caused by earthquakes, volcanoes, landslides and debris flows. To effectively allocate resources and create emergency plans we need an understanding of the risk factors of the region. Understanding the source events of destructive tsunamis of the past are critical to understanding the these risk factors. We expand upon previous work focusing on earthquake-generated tsunamis to consider landslide-generated tsunamis. Using Bayesian inference and modern scientific computing we construct a posterior distribution of potential landslide sources based on anecdotal data of historically observed tsunamis. After collecting 30,000 samples we find a landslide source event provides a reasonable match to our anecdotal accounts. However, viable landslides may be on the edge of what is physically possible. Future work creating a coupled landslide-earthquake model may account for the weaknesses with having a solely landslide or earthquake source event.

Seismic hazard and microzonation of cities enable to characterize the potential seismic areas that need to be taken into account when designing new structures or retrofitting the existing ones. Study of seismic hazard and preparation of geotechnical microzonation maps will provide an effective solution for city planning and input to earthquake resistant design of structures in an area. Seismic hazard is the study of expected earthquake ground motions at any point on the earth. Microzonation is the process of sub division of region in to number of zones based on the earthquake effects in the local scale. Seismic microzonation is the process of estimating response of soil layers under earthquake excitation and thus the variation of ground motion characteristic on the ground surface. Geotechnical site characterization and assessment of site response during earthquakes is one of the crucial phases of seismic microzonation with respect to ground shaking intensity, attenuation, amplification rating and liquefaction susceptibility. Microzonation mapping of seismic hazards can be expressed in relative or absolute terms, on an urban block-by-block scale, based on local soil conditions (such as soil types) that affect ground shaking levels or vulnerability to soil liquefaction. Such maps would provide general guidelines for integrated planning of cities and in positioning the types of new structures that are most suited to an area, along with information on the relative damage potential of the existing structures in a region. In the present study an attempt has been made to characterize the site and to study the seismic hazard analysis considering the local site effects and to develop microzonation maps for Bangalore. Seismic hazard analysis and microzonation of Bangalore is addressed in this study in three parts: In the first part, estimation of seismic hazard using seismotectonic and geological information. Second part deals about site characterization using geotechnical and shallow geophysical techniques. An area of 220 sq.km, encompassing Bangalore Municipal Corporation has been chosen as the study area in this part of the investigation. There were over 150 lakes, though most of them are dried up due to erosion and encroachments leaving only 64 at present in an area of 220 sq. km and emphasizing the need to study site effects. In the last part, local site effects are assessed by carrying out one-dimensional (1-D) ground response analysis (using the program SHAKE 2000) using both borehole SPT data and shear wave velocity survey data within an area of 220 sq. km. Further, field experiments using microtremor studies have also been carried out (jointly with NGRI) for evaluation of predominant frequency of the soil columns. The same has been assessed using 1-D ground response analysis and compared with microtremor results. Further, Seed and Idriss simplified approach has been adopted to evaluate the liquefaction susceptibility and liquefaction resistance assessment. Microzonation maps have been prepared for Bangalore city covering 220 sq. km area on a scale of 1:20000. Deterministic Seismic Hazard Analysis (DSHA) for Bangalore has been carried out by considering the past earthquakes, assumed subsurface fault rupture lengths and point source synthetic ground motion model. The seismic sources for region have been collected by considering seismotectonic atlas map of India and lineaments identified from satellite remote sensing images. Analysis of lineaments and faults help in understanding the regional seismotectonic activity of the area. Maximum Credible Earthquake (MCE) has been determined by considering the regional seismotectonic activity in about 350 km radius around Bangalore. Earthquake data are collected from United State Geological Survey (USGS), Indian Metrological Department (IMD), New Delhi; Geological Survey of India (GSI) and Amateur Seismic Centre (ASC), National Geophysical Research Institute (NGRI),Hyderabad; Centre for Earth Science Studies (CESS), Akkulam, Kerala; Gauribindanur (GB) Seismic station and other public domain sites. Source magnitude for each source is chosen from the maximum reported past earthquake close to that source and shortest distance from each source to Bangalore is arrived from the newly prepared seismotectonic map of the area. Using these details, and, attenuation relation developed for southern India by Iyengar and Raghukanth (2004), the peak ground acceleration (PGA) has been estimated. A parametric study has been carried out to find fault subsurface rupture length using past earthquake data and Wells and Coppersmith (1994) relation between the subsurface lengths versus earthquake magnitudes. Further seismological model developed by Boore (1983, 2003) SMSIM program has been used to generate synthetic ground motions from vulnerable sources identified in above two methods. From the above three approaches maximum PGA of 0.15g was estimated for Bangalore. This value was obtained for a maximum credible earthquake (MCE) having a moment magnitude of 5.1 from a source of Mandya-Channapatna-Bangalore lineament. Considering this lineament and MCE, a synthetic ground motion has been generated for 850 borehole locations and they are used to prepare PGA map at rock level. The past seismic data has been collected for almost 200 years from different sources such as IMD, BARC (Gauribidanur array), NGRI, CESS, ASC center, USGS, and other public domain data. The seismic data is seen to be homogenous for the last four decades irrespective of the magnitude. Seismic parameters were then evaluated using the data corresponding to the last four decades and also the mixed data (using Kijko’s analysis) for Bangalore region, which are found to be comparable with the earlier reported seismic parameters for south India. The probabilities of distance, magnitude and peak ground acceleration have been evaluated for the six most vulnerable sources using PSHA (Probabilistic Seismic Hazard Analysis). The mean annual rate of exceedance has been calculated for all the six sources at the rock level. The cumulative probability hazard curves have been generated at the bedrock level for peak ground acceleration and spectral acceleration. The spectral acceleration calculation corresponding to a period of 1sec and 5% damping are evaluated. For the design of structures, uniform hazard response spectrum (UHRS) at rock level is developed for the 5% damping corresponding to 10% probability of exceedance in 50 years. The peak ground acceleration (PGA) values corresponding to 10% probability of exceedance in 50 years are comparable to the PGA values obtained in deterministic seismic hazard analysis (DSHA) and higher than Global Seismic Hazard Assessment Program (GSHAP) maps of Bhatia et.al (1997) for the Indian shield area. The 3-D subsurface model with geotechnical data has been generated for site characterization of Bangalore. The base map of Bangalore city (220sq.km) with several layers of information (such as Outer and Administrative boundaries, Contours, Highways, Major roads, Minor roads, Streets, Rail roads, Water bodies, Drains, Landmarks and Borehole locations) has been generated. GIS database for collating and synthesizing geotechnical data available with different sources and 3-dimensional view of soil stratum presenting various geotechnical parameters with depth in appropriate format has been developed. In the context of prediction of reduced level of rock (called as “engineering rock depth” corresponding to about Vs > 700 m/sec) in the subsurface of Bangalore and their spatial variability evaluated using Artificial Neural Network (ANN). Observed SPT ‘N’ values are corrected by applying necessary corrections, which can be used for engineering studies such as site response and liquefaction analysis. Site characterization has also been carried out using measured shear wave velocity with the help of shear wave velocity survey using MASW. MASW (Multichannel Analysis of Surface Wave) is a geophysical method, which generates a shear-wave velocity (Vs) profile (i.e., Vs versus depth) by analyzing Raleigh-type surface waves on a multichannel record. MASW system consisting of 24 channels Geode seismograph with 24 geophones of 4.5 Hz capacity were used in this investigation. The shear wave velocity of Bangalore subsurface soil has been measured and correlation has been developed for shear wave velocity (Vs) with the standard penetration tests (SPT) corrected ‘N’ values. About 58 one-dimensional (1-D) MASW surveys and 20 two-dimensional (2-D) MASW surveys has been carried out with in 220 sq.km Bangalore urban area. Dispersion curves and shear velocity 1-D and 2-D have been evaluated using SurfSeis software. Using 1-dimensional shear wave velocity, the average shear wave velocity of Bangalore soil has been evaluated for depths of 5m, 10m, 15m, 20m, 25m and 30m (Vs30) depths. The sub soil classification has been carried out for local site effect evaluation based on average shear wave velocity of 30m depth (Vs30) of sites using NEHRP (National Earthquake Hazard Research Programme) and IBC (International Building Code) classification. Bangalore falls into site class D type of soil. Mapping clearly indicates that the depth of soil obtained from MASW is closely matching with the soil layers in the bore logs. The measured shear wave velocity at 38 locations close to SPT boreholes, which are used to generate the correlation between the shear wave velocity and corrected ‘N’ values using a power fit. Also, developed relationship between shear wave velocity and corrected ‘N’ values corresponds well with the published relationships of Japan Road Association. Bangalore city, a fast growing urban center, with low to moderate earthquake history and highly altered soil structure (due to large reclamation of land) is been the focus of this work. There were over 150 lakes, though most of them are dried up due to erosion and encroachments leaving only 64 at present in an area of 220 sq km. In the present study, an attempt has been made to assess the site response using geotechnical, geophysical data and field studies. The subsurface profiles of the study area within 220sq.km area was represented by 170 geotechnical bore logs and 58 shear wave velocity profiles obtained by MASW survey. The data from these geotechnical and geophysical technique have been used to study the site response. These soil properties and synthetic ground motions for each borehole locations are further used to study the local site effects by conducting one-dimensional ground response analysis using the program SHAKE2000. The response and amplification spectrum have been evaluated for each layer of borehole location. The natural period of the soil column, peak spectral acceleration and frequency at peak spectral acceleration of each borehole has been evaluated and presented as maps. Predominant frequency obtained from both methods is compared; the correlation between corrected SPT ‘N’ value and low strain shear modulus has been generated. The noise was recorded at 54 different locations in 220sq.km area of Bangalore city using L4-3D short period sensors (CMG3T) equipped with digital data acquisition system. Predominant frequency obtained from ground response studies and microtremor measurement is comparable. To study the liquefaction hazard in Bangalore, the liquefaction hazard assessment has been carried out using standard penetration test (SPT) data and soil properties. Factor of Safety against liquefaction of soil layer has been evaluated based on the simplified procedure of Seed and Idriss (1971) and subsequent revisions of Seed et al (1983, 1985), Youd et al (2001) and Cetin et al (2004). Cyclic Stress Ratio (CSR) resulting from earthquake loading is calculated by considering moment magnitude of 5.1 and amplified peak ground acceleration. Cyclic Resistant Ratio (CRR) is arrived using the corrected SPT ‘N’ values and soil properties. Factor of safety against liquefaction is calculated using stress ratios and accounting necessary magnitude scaling factor for maximum credible earthquake. A simple spread sheet was developed to carryout the calculation for each bore log. The factor of safety against liquefaction is grouped together for the purpose of classification of Bangalore (220 sq. km) area for a liquefaction hazards. Using 2-D base map of Bangalore city, the liquefaction hazard map was prepared using AutoCAD and Arc GIS packages. The results are grouped as four groups for mapping and presented in the form of 2-dimensional maps. Liquefaction possibilities are also assessed conducting laboratory cyclic triaxial test using undisturbed soil samples collected at few locations.

Earthquake is undoubtedly one of the greatest natural disasters that can induce serious structural damage and huge losses of properties and lives. The resulting destructive consequences not only have made structural seismic analysis and design much more important but have impelled the necessity of more realistic representation of ground motions, such as inclusion of ground motion spatial variations in earthquake modelling and seismic analysis and design of structures. Recorded seismic ground motions exhibit spatial variations in their amplitudes and phases, and the spatial variabilities have an important effect on the responses of structures extended in space, such as long span bridges. Because of the multi-parametric nature and the complexity of the problems, the development of specific design provisions on spatial variabilities of ground motions in modern seismic codes has been impeded. Eurocode 8 is currently the only seismic standard worldwide that gives a set of detailed guidelines to explicitly tackle spatial variabilities of ground motions in bridge design, providing both a simplified design scheme and an analytical approach. However, there is gap between the code-specified provisions in Eurocode 8 and the realistic representation of spatially varying ground motions (SVGM) and the corresponding stochastic vibration analysis (SVA) approaches. This study is devoted to bridge this gap on modelling of SVGM and development of SVA approaches for structures extended in space under SVGM. A complete and realistic SVGM representation approach is developed by accounting for the incoherence effect, wave-passage effect, site-response effect, ground motion nonstationarity, tridirectionality, and spectra-compatibility. This effort brings together various aspects regarding rational seismic scenarios determination, comprehensive methods of accounting for varying site effects, conditional modelling of SVGM nonstationarity, and code-specified ground motion spectra-compatibility. A comprehensive, systematic, and efficient SVA methodology is derived for long span structures under tridirectional nonstationary SVGM. An absolute-response-oriented scheme of pseudo-excitation method and an improved high precision direct integration method are proposed to reduce the enormous computational effort of conventional nonstationary SVA. A scheme accounting for tridirectional varying site-response effect is incorporated in the nonstationary SVA scheme systematically. The proposed highly efficient and accurate SVA approach is implemented and verified in a general finite element analysis platform to make it readily applicable in SVA of complex structures. Based on the proposed SVA approach, parametric studies of two practical long span bridges under SVGM are conducted. To account for spatial randomness and variability of soil properties in soil-structure interaction analysis of structures under SVGM, a meshfree-Galerkin approach is proposed within the Karhunen-Loeve expansion scheme for representation of spatial soil properties modelled as a random field. The meshfree shape functions are proposed as a set of basis functions in the Galerkin scheme to solve integral equation of Karhunen-Loeve expansion, with a proposed optimization scheme in treating the compatibility between the target and analytical covariance models. The accuracy and validity of the meshfree-Galerkin scheme are assessed and demonstrated by representation of covariance models for various homogeneous and nonhomogeneous spatial fields. The developed modelling approaches of SVGM and the derived analytical SVA approaches can be applied to provide more refined solutions for quantitatively assessing code-specified design provisions and developing new design provisions. The proposed meshfree-Galerkin approach can be used to account for spatial randomness and variability of soil properties in soil-structure interaction analysis.

Mankind is facing the problem due to earthquake hazard since prehistoric times. Many of the developed and developing countries are under constant threats from earthquakes hazards. Theories of plate tectonics and engineering seismology have helped to understand earthquakes and also to predicate earthquake hazards on a regional scale. However, the regional scale hazard mapping in terms of seismic zonation has been not fully implemented in many of the developing countries like India. Agglomerations of large population in the Indian cities and poor constructions have raised the risk due to various possible seismic hazards. First and foremost step towards hazard reduction is estimation of the seismic hazards in regional scale. Objective of this study is to estimate the seismic hazard parameters for Lucknow, a part of Indo-Gangetic Basin (IGB) and develop regional scale microzonation map. Lucknow is a highly populated city which is located close to the active seismic belt of Himalaya. This belt came into existence during the Cenozoic era (40-50 million years ago) and is a constant source of seismic threats. Many of the devastating earthquakes which have happened since prehistoric times such as 1255 Nepal, 1555 Srinagar, 1737 Kolkata, 1803 Nepal, 1833 Kathmandu, 1897 Shillong, 1905 Kangra, 1934 Bihar-Nepal, 1950 Assam and 2005 Kashmir. Historic evidences show that many of these earthquakes had caused fatalities even up to 0.1 million. At present, in the light of building up strains and non-occurrence of a great event in between 1905 Kangra earthquake and 1934 Bihar-Nepal earthquake regions the stretch has been highlighted as central seismic gap. This location may have high potential of great earthquakes in the near future. Geodetic studies in these locations indicate a possible slip of 9.5 m which may cause an event of magnitude 8.7 on Richter scale in the central seismic gap. Lucknow, the capital of Uttar Pradesh has a population of 2.8 million as per Census 2011. It lies in ZONE III as per IS1893: 2002 and can be called as moderate seismic region. However, the city falls within 350 km radial distance from Main Boundary Thrust (MBT) and active regional seismic source of the Lucknow-Faizabad fault. Considering the ongoing seismicity of Himalayan region and the Lucknow-Faizabad fault, this city is under high seismic threat. Hence a comprehensive study of understanding the earthquake hazards on a regional scale for the Lucknow is needed. In this work the seismic microzonation of Lucknow has been attempted. The whole thesis is divided into 11 chapters. A detailed discussion on the importance of this study, seismicity of Lucknow, and methodology adopted for detailed seismic hazard assessment and microzonation are presented in first three chapters. Development of region specific Ground Motion Prediction Equation (GMPE) and seismic hazard estimation at bedrock level using highly ranked GMPEs are presented in Chapters 4 and 5 respectively. Subsurface lithology, measurement of dynamic soil properties and correlations are essential to assess region specific site effects and liquefaction potential. Discussion on the experimental studies, subsurface profiling using geotechnical and geophysical tests results and correlation between shear wave velocity (SWV) and standard penetration test (SPT) N values are presented in Chapter 6. Detailed shear wave velocity profiling with seismic site classification and ground response parameters considering multiple ground motion data are discussed in Chapters 7 and 8. Chapters 9 and 10 present the assessment of liquefaction potential and determination of hazard index with microzonation maps respectively. Conclusions derived from each chapter are presented in Chapter 11. A brief summary of the work is presented below: Attenuation relations or GMPEs are important component of any seismic hazard analysis which controls accurate prediction of the hazard values. Even though the Himalayas have experienced great earthquakes since ancient times, suitable GMPEs which are applicable for a wide range of distance and magnitude are limited. Most of the available regional GMPEs were developed considering limited recorded data and/or pure synthetic ground motion data. This chapter presents development of a regional GMPE considering both the recorded as well as synthetic ground motions. In total 14 earthquakes consisting of 10 events with recorded data and 4 historic events with Isoseismal maps are used for the same. Synthetic ground motions based on finite fault model have been generated at unavailable locations for recorded events and complete range distances for historic earthquakes. Model parameters for synthetic ground motion were arrived by detailed parametric study and from literatures. A concept of Apparent Stations (AS) has been used to generate synthetic ground motion in a wide range of distance as well as direction around the epicenter. Synthetic ground motion data is validated by comparing with available recorded data and peak ground acceleration (PGA) from Isoseismal maps. A new GMPE has been developed based on two step stratified regression procedure considering the combined dataset of recorded and synthetic ground motions. The new GMPE is validated by comparing with three recently recorded earthquakes events. GMPE proposed in this study is capable of predicting PGA values close to recorded data and spectral acceleration up to period of 2 seconds. Comparison of new GMPE with the recorded data of recent earthquakes shows a good matching of ground motion as well as response spectra. The new GMPE is applicable for wide range of earthquake magnitudes from 5 to 9 on Mw scale. Reduction of future earthquake hazard is possible if hazard values are predicted precisely. A detailed seismic hazard analysis is carried out in this study considering deterministic and probabilistic approaches. New seismotectonic map has been generated for Lucknow considering a radial distance of 350 km around the city centre, which also covers active Himalayan plate boundaries. Past earthquakes within the seismotectonic region have been collected from United State Geological Survey (USGS), Northern California Earthquake Data Centre (NCEDC), Indian Meteorological Department (IMD), Seismic Atlas of India and its Environs (SEISAT) etc. A total of 1831 events with all the magnitude range were obtained. Collected events were homogenized, declustered and filtered for Mw ≥ 4 events. A total of 496 events were found within the seismic study region. Well delineated seismic sources are compiled from SEISAT. Superimposing the earthquake catalogue on the source map, a seismotectonic map of Lucknow was generated. A total of 47 faults which have experienced earthquake magnitude of 4 and above are found which are used for seismic hazard analysis. Based on the distribution of earthquake events on the seismotectonic map, two regions have been identified. Region I which shows high density of seismic events in the area in and around of Main Boundary Thrust (MBT) and Region II which consists of area surrounding Lucknow with sparse distribution of earthquake events. Data completeness analysis and estimation of seismic parameter “a” and “b” are carried out separately for both the regions. Based on the analysis, available earthquake data is complete for a period of 80 years in both the regions. Using the complete data set, the regional recurrence relations have been developed. It shows a “b” value of 0.86 for region I and 0.9 for Region II which are found comparable with earlier studies. Maximum possible earthquake magnitude in each source has been estimated using observed magnitude and doubly truncated Gutenberg-Richter relation. The study area of Lucknow is divided into 0.015o x 0.015o grid size and PGA at each grid has been estimated by considering all sources and the three GMPEs. A Matlab code was generated for seismic hazard analysis and maximum PGA value at each grid point was determined and mapped. Deterministic seismic hazard analysis (DSHA) shows that maximum expected PGA values at bedrock level varies from 0.05g in the eastern part to 0.13g in the northern region. Response spectrum at city centre is also developed up to a period of 2 seconds. Further, Probabilistic seismic hazard analysis (PSHA) has been carried out and PGA values for 10 % and 2 % probability of exceedence in 50 years have been estimated and mapped. PSHA for 10 % probability shows PGA variation from 0.035g in the eastern parts to 0.07g in the western and northern parts of Lucknow. Similarly PSHA for 2 % probability of exceedence indicates PGA variation from 0.07g in the eastern parts while the northern parts are expecting PGA of 0.13g. Uniform hazard spectra are also developed for 2 % and 10 % probability for a period of up to 2 seconds. The seismic hazard analyses in this study show that the northern and western parts of Lucknow are more vulnerable when compared to other part. Bedrock hazard values completely change due to subsoil properties when it reaches the surface. A detailed geophysical and geotechnical investigation has been carried out for subsoil profiling and seismic site classification. The study area has been divided into grids of 2 km x 2 km and roughly one geophysical test using MASW (Multichannel Analysis Surface Wave) has been carried out in each grid and the shear wave velocity (SWV) profiles of subsoil layers are obtained. A total of 47 MASW tests have been carried out and which are uniformly distributed in Lucknow. In addition, 12 boreholes have also been drilled with necessary sampling and measurement of N-SPT values at 1.5 m interval till a depth of 30 m. Further, 11 more borelog reports are collected from the same agency hired for drilling the boreholes. Necessary laboratory tests are conducted on disturbed and undisturbed soil samples for soil classification and density measurement. Based on the subsoil informations obtained from these boreholes, two cross-sections up to a depth of 30 m have been generated. These cross-sections show the presence of silty sand in the top 10 m at most of the locations followed by clayey sand of low to medium compressibility till a depth of 30 m. In between the sand and clay traces of silt were also been found in many locations. In addition to these boreholes, 20 deeper boreholes (depth ≥150 m) are collected from Jal Nigam (Water Corporation) Lucknow, Government of Uttar Pradesh. Typical cross-section along the alignment of these deeper boreholes has been generated up to 150 m depth. This cross-section shows the presence of fine sand near Gomati while other locations are occupied by surface clayey sand. Also, the medium sand has been found in the western part of the city at a depth of 110 m which continues till 150 m depth. On careful examination of MASW and boreholes with N-SPT, 17 locations are found very close and SWV and N-SPT values are available up to 30 m depth. These SWV and N-SPT values are complied and used to develop correlations between SWV and N-SPT for sandy soil, clayey soil and all soil types. This correlation is the first correlation for IGB soil deposits considered measured data up to 30 m. The new correlation is verified graphically using normal consistency ratio and standard percentage error with respect to measured N-SPT and SWV. Further, SWV and N-SPT profiles are used Another important earthquake induced hazard is liquefaction. Even though many historic earthquakes caused liquefaction in India, very limited attempt has been made to map liquefaction potential in IGB. In this study, a detailed liquefaction analysis has been carried out for Lucknow a part of Ganga Basin to map liquefaction potential. Initially susceptibility of liquefaction for soil deposits has been assessed by comparing the grain size distribution curve obtained from laboratory tests with the range of grain size distribution for potentially liquefiable soils. Most of surface soil deposits in the study area are susceptible to liquefaction. At all the 23 borehole locations, measured N-SPT values are corrected for (a) Overburden Pressure (CN), (b) Hammer energy (CE), (c) Borehole diameter (CB), (d) presence or absence of liner (CS), (e) Rod length (CR) and (f) fines content (Cfines). Surface PGA values at each borehole locations are used to estimate Cyclic Stress Ratio (CSR). Corrected N-SPT values [(N1)60CS] are used to estimate Cyclic Resistance Ratio (CRR) at each layer. CSR and CRR values are used to estimate Factor of Safety (FOS) against liquefaction in each layer. Least factor safety values are indentified from each location and presented liquefaction factor of safety map for average and maximum amplified PGA values. These maps highlight that northern, western and central parts of Lucknow are very critical to critical against liquefaction while southern parts shows moderate to low critical area. The entire alignment of river Gomati falls in very critical to critical regions for liquefaction. Least FOS shows worst scenario and does not account thickness of liquefiable soil layers. Further, these FOS values are used to determine Liquefaction Potential Index (LPI) of each site and developed LPI map. Based on LPI map, the Gomati is found as high to very high liquefaction potential region. Southern and the central parts of Lucknow show low to moderate liquefaction potential while the northern and western Lucknow has moderate to high liquefaction potential. All possible seismic hazards maps for Lucknow have been combined to develop final microzonation map in terms of hazard index values. Hazard index maps are prepared by combining rock PGA map, site classification map in terms of shear wave velocity, amplification factor map, and FOS map and predominant period map by adopting Analytical Hierarchy Process (AHP). All these parameters have been given here in the order starting with maximum weight of 6 for PGA to lower weight of 1 for predominant frequency. Normalized weights of each parameter have been estimated. Depending upon the variation of each hazard parameter values, three to five ranks are assigned and the normalized ranks are calculated. Final hazard index values have been estimated by multiplying normalized ranks of each parameter with the normalized weights. Microzonation map has been generated by mapping hazard index values. Three maps were generated based on DSHA, PSHA for 2% and 10 % probability of exceedence in 50 years. Hazard index maps from DSHA and PSHA for 2 % probability show similar pattern. Higher hazard index were obtained in northern and western parts of Lucknow and lower values in others. The new microzonation maps can help in dividing the Lucknow into three parts as high area i.e. North western part, moderate hazard area i.e. central part and low hazard area which covers southern and eastern parts of Lucknow. This microzonation is different from the current seismic code where all area is lumped in one zone without detailed assessment of different earthquake hazard parameters. Finally this study brings out first region specific GMPE considering recorded and synthetic ground monitions for wide range of magnitudes and distances. Proposed GMPE can also be used in other part of the Himalayan region as it matches well with the highly ranked GMPEs. Detailed rock level PGA map has been generated for Lucknow considering DSHA and PSHA. A detailed geotechnical and geophysical experiments are carried out in Lucknow. These results are used to develop correction between SWV and N-SPT values for soil deposit in IGB and site classification maps for the study area. Amplification and liquefaction potential of Lucknow are estimated by considering multiple ground motions data to account different earthquake ground motion amplitude, duration and frequency, which is unique in the seismic microzonation study.

This thesis addresses two fundamental topics in Engineering Seismology; the application of Probabilistic Seismic Hazard Analysis (PSHA) methodology, and the estimation of measures of Strong Ground Motion. These two topics, while being related, are presented as separate sections. In the first section, state-of-the-art PSHA methodologies are applied to various sites in the Buller Region, South Island, New Zealand. These sites are deemed critical to the maintenance of economic stability in the region. A fault-source based seismicity model is developed for the region that is consistent with the governing tectonic loading, and seismic moment release of the region. In attempting to ensure this consistency the apparent anomaly between the rates of activity dictated by deformation throughout the Quaternary, and rates of activity dictated by observed seismicity is addressed. Individual fault source activity is determined following the application of a Bayesian Inference procedure in which observed earthquake events are attributed to causative faults in the study region. The activity of fault sources, in general, is assumed to be governed by bounded power law behaviour. An exception is made for the Alpine Fault which is modelled as a purely characteristic source. The calculation of rates of exceedance of various ground motion indices is made using a combination of Poissonian and time-dependent earthquake occurrence models. The various ground motion indices for which rates of exceedance are determined include peak ground acceleration, ordinates of 5% damped Spectral Acceleration, and Arias Intensity. The total hazard determined for each of these ground motion measures is decomposed using a four dimensional disaggregation procedure. From this disaggregation procedure, design earthquake scenarios are specified for the sites that are considered. The second part of the thesis is concerned with the estimation of ground motion measures that are more informative than the existing scalar measures that are available for use in New Zealand. Models are developed for the prediction of Fourier Amplitude Spectra (FAS) as well as Arias Intensity for use in the New Zealand environment. The FAS model can be used to generate ground motion time histories for use in structural and geotechnical analyses. Arias Intensity has been shown to be an important strong motion measure due to its positive correlation with damage in short period structures as well as its utility in predicting the onset of liquefaction and landslides. The models are based upon the analysis of a dataset of New Zealand Strong Motion records as well as supplementary near field records from major overseas events. While the two measures of ground motion intensity are strongly related, different methods have been adopted in order to develop the models. As part of the methodology used for the FAS model, Monte Carlo simulation coupled with a simple ray tracing procedure is employed to estimate source spectra from various New Zealand earthquakes and, consequently, a magnitude - corner-frequency relationship is obtained. In general, the parameters of the predictive equations are determined using the most state-of-the-art mixed effects regression procedures.

Tee present research focuses on seismic hazard studies for the states of Tripura and Mizoram in the North-East India with taking into account the complex sesismotectonic characteristics of the region. This area is more prone to earthquake hazard due to complex subsurface geology, peculiar topographical distribution, continuous crustal deformation due to the under thrusting of Indian and the Eurasian plates, a possible seismic gap, and many active intraplate sources identified within this region. The study area encompasses major seismic source zones such as Indo Burmese Range (IBR), Shillong Plateau (SP), Eastern Himalayan arc (EH), Bengal Basin (BB), Mishmi Thrust (MT) and Naga Thrust (NT). Five historical earthquakes of magnitude Mw>8 have been listed in the study area and 15 events of magnitude Mw>7 have occurred in last 100 years. Indian seismic code BIS-1893-2002 places the study area with a high level of seismic hazard in the country (i.e. seismic zone V). More than 60% of the area is hilly steep-terrain in nature and the altitude varies from 0 to 3000 meters. Recent works have located a seismic gap, known as the Assam gap since 1950 between the EH, SP, and IBR with the Eurasian plate. Various researchers have estimated the return period, and a large size earthquake is expected in this region any time in future. The area is also highly prone to liquefaction, since rivers in Tripura (Gomati, Howrah, Dhalai, Manu, Bijay, Jeri, Feni) and the rivers in Mizoram (Chhimtuipui, Tlawng, Tut, Tuirial and Tuivawl etc.) are scattered throughout the study area where soil deposits are of sedimentary type. In 2011, both the states together have experienced 37 earthquakes (including foreshocks and aftershocks) with magnitudes ranging from 2.9 to 6.9. Of these events, there were 23 earthquakes (M>4) of magnitudes M6.4 (Feb 4th 2011), M6.7 (March 24th 2011), M6.9 (Sept.18th 2011), M6.4 (October 30th 2011), M6.9 (Dec 13th 2011), M5.8 (Nov 21st 2011), M5 (Aug 18th 2011), M4.9 (July 28th 2011), M4.6 (Dec 15th 2011), M4.6 (Jan 21st 2011), M4.5 (Dec 9th 2011), M4.5 (Oct 21th 2011), M4.5 (Oct 17th 2011), M4.5 (Sept 18th 2011), M4.3 (Oct 10th 2011), M4.3 (Sept 22nd 2011), M4.3 (April 4th 2011), M4.2 (Sept 9th 2011), M4.2 (Sept 18th 2011), M4.1 (April 29th 2011), M4.1 (Feb 22nd 2011), M4 (June 9th 2011), and M4 (Dec 2nd 2011) which occurred within this region [source: IMD (Indian Metrological Department), India]. The earthquake (M6.9) that occurred on Sept. 18th 2011 is known as the Sikkim earthquake, and it caused immense destruction including building collapse, landslides, causalities, disrupted connectivity by road damages and other infrastructural damages in Sikkim state as well as the entire North-East India. In the cities of Agartala and Aizawl of Tripura and Mizoram, construction of high rise building is highly restricted by the Government. Being the capital city, many modern infrastructures are still pending for growth of the city planning. Although many researchers have studied and reported about the status of seismicity in North-East Region of India, very few detailed studies have been carried out in this region except Guwahati, Sikkim and Manipur where almost the whole of the study area is highly vulnerable to severe shaking, amplification, liquefaction, and landslide. From the available literature, no specific study exists for Tripura and Mizoram till date. In the present research, seismic hazard assessment has been performed based on spatial-temporal distribution of seismicity and fault rupture characteristics of the region. The seismic events were collected from regions covering about 500 km from the political boundary of the study area. The earthquake data were collected from various national and international seismological agencies such as the IMD, Geological Survey of India (GSI), United State Geological Survey (USGS), and International Seismological Centre (ISC) etc. As the collected events were in different magnitude scales, all the events were homogenized to a unified moment magnitude scale using recent magnitude conversion relations (region specific) developed by the authors for North-East Region of India. The dependent events (foreshocks and aftershocks) were removed using declustering algorithm and in total 3251 declustered events (main shocks) were identified in the study area since 1731 to 2011. The data set contains 825 events of MW < 4, 1279 events of MW from 4 to 4.9, 996 events MW from 5 to 5.9, 131 events MW from 6 to 6.9, 15 events MW from 7 to 7.9 and 5 events MW ≥8. The statistical analysis was carried out for data completeness (Stepp, 1972). The whole region was divided into six seismic source zones based on the updated seismicity characteristics, fault rupture mechanism, size of earthquake magnitude and the epicentral depth. Separate catalogs were used for each zone, and seismicity parameters a and b were estimated for each source zone and other necessary parameters such as mean magnitude (Mmean), Mmax, Mmin, Mc and recurrence periods were also estimated. Toposheets/vector maps of the study area were collected and seismic sources were identified and characterized as line, point, and areal sources. Linear seismic sources were identified from the Seismotectonic atlas (SEISAT, 2000) published by the GSI, in addition to the source details collected from available literature and remote sensing images. The SEISAT map contains 43 maps presented in 42 sheets covering entire India and adjacent countries with 1:1million scale. Sheets representing the features of the study area were scanned, digitized and georeferenced using MapInfo 10.0 version. After this, tectonic features and seismicity events were superimposed on the map of the study area to prepare a Seismotectonic Map with a scale of 1:1million. In seismic hazard assessment, a state of art well known methodologies (deterministic and probabilistic) was used. In deterministic seismic hazard analysis (DSHA) procedure, hazard assessment is based on the minimum distance between sources to site considering the maximum magnitude occurred at each source. In hazard estimation procedure a lot of uncertainties are involved, which can be explained by probabilistic seismic hazard analysis (PSHA) procedure related to the source, magnitude, distance, and local site conditions. The attenuation relations proposed by Atkinson and Boore (2003), and Gupta (2010) are used in this analysis. Because in this region two type activities are mostly observed, regions such as SP, and EH are under plate boundary zone whereas IBR is under subduction process. These equations (GMPEs) were validated with the observed PGA (Peak ground acceleration) values before use in the hazard evaluation. The hazard curves for all six major sources were prepared and compiled to get the total hazard curve which represents the cumulative hazard of all sources. Evaluation of PGA, Sa (0.2s and 1.0s) parameters at bedrock level were estimated considering a grid size of 5 km x 5 km, and spectral acceleration values corresponding to a certain level of probability (2% and 10%) were done to develop uniform hazard spectrum (UHS) for both the cities (Agartala and Aizawl). To carry out the seismic microzonation of Agartala and Aizawl cities, a detailed study using geotechnical and geophysical data has been carried out for site characterization and evaluation of site response according to NEHRP (National Earthquake Hazard Response Program) soil classifications (A, B, C, D, and E-type). Seismic site characterization, which is the basic requirement for seismic microzonation and site response studies of an area. Site characterization helps to have the idea about the average dynamic behavior of soil deposits, and thus helps to evaluate the surface level response. A series of geophysical tests at selected locations have been conducted using multichannel analysis of surface waves (MASW) technique, which is an advanced method to obtain direct shear wave velocity profiles from in situ measurements for both the cities. Based on the present study a major part of Agartala city falls under site class D, very few portions come under site class E. On the other hand, Aizawl city comes under site class C. Next, a detailed site response analysis has been carried out for both the cities. This study addresses the influence of local geology and soil conditions on incoming ground motion. Subsurface geotechnical (SPT) and geophysical (MASW) data have been obtained and used to estimate surface level response. The vulnerable seismic source has been identified based on DSHA. Due to the lack of strong motion time history of the study area, synthetic ground motion time histories have been generated using point source seismological model (Boore 2003) at bedrock level based on fault rupture parameters such as stress drop, quality factor, frequency range, magnitude, hypocentral distance etc. Dynamic properties such as the shear modulus (G) and damping ratios (ζ) have been evaluated from the soil properties obtained from SPT bore log data collected from different agencies such as PWD (Public works Department), and Urban Development Dept. of the State Government, in situ shear wave velocity has been obtained from MASW survey in different locations, and following this, a site response analysis has been carried out using SHAKE-2000 to calculate the responses at the ground surface in combination of different magnitudes, distances and epicentral depth for a particular site class. An amplification factor was estimated as the ratio of the PGA at the ground surface to the PGA at bedrock level, a regression analysis was carried out to evaluate period dependant site coefficients, and hence, the period dependant hazard impact on the ground surface could be calculated to obtain the spatial variation of PGA over the study area. Further, liquefaction potential of the site (Agartala) was also evaluated using available SPT bore log data collected and using presently estimated surface level PGA. The results are presented in the form of liquefaction hazard map representing as a Factor of safety (FS) against liquefaction with various depths such as 1.5m, 10m, and 15m respectively. It has been seen that Agartala city shows highly prone to liquefaction even up to 15 m depth. Hence, site specific study is highly recommended for implementing any important project. The liquefaction hazard assessment could not be conducted for the Aizawl city because of non availability of the SPT-N data, however, the city stands on hills/mountains, and therefore, such a study is not applicable in this area. Further, seismic microzonation maps for both the cities have been prepared considering Analytical Hierarchy Process (AHP) which support to the Eigen value properties of the system. Two types of hazard maps have been developed, one using deterministic and another using the probabilistic seismic microzonation maps. These maps can be directly used as inputs for earthquake resistant design, and disaster mitigation planning of the study area. However, an investigation has also been made in forecasting a major earthquake (Mw>6) in North-East India using several probabilistic models such as Gamma, Weibull and lognormal models. IBR and EH show a high probability of occurrences in the next 5 years (i.e. 2013-2018) with >90% probability.

One of the most difficult tasks towards designing earthquake resistant structures is the determination of critical earthquakes. Conceptually, these are the ground motions that would induce the critical response in the structures being designed. The quantification of this concept, however, is not easy. Unlike the linear response of a structure, which can often be obtained by using a single spectrally modified ground acceleration history, the nonlinear response is strongly dependent on the phasing of ground motion and the detailed shape of its spectrum. This necessitates the use of a suite (bin) of ground acceleration histories having phasing and spectral shapes appropriate for the characteristics of the earthquake source, wave propagation path, and site conditions that control the design spectrum. Further, these suites of records may have to be scaled to match the design spectrum over a period range of interest, rotated into strike-normal and strike-parallel directions for near-fault effects, and modified for local site conditions before they can be input into time-domain nonlinear analysis of structures. The generation of these acceleration histories is cumbersome and daunting. This is especially so due to the sheer magnitude of the data processing involved. The purpose of this thesis is the development and documentation of PC-based computational tools (hereinafter called EQTools) to provide a rapid and consistent means towards systematic assembly of representative strong ground motions and their characterization, evaluation, and modification within a performance-based seismic design framework. The application is graphics-intensive and every effort has been made to make it as user-friendly as possible. The application seeks to provide processed data which will help the user address the problem of determination of the critical earthquakes. The various computational tools developed in EQTools facilitate the identification of severity and damage potential of more than 700 components of recorded earthquake ground motions. The application also includes computational tools to estimate the ground motion parameters for different geographical and tectonic environments, and perform one-dimensional linear/nonlinear site response analysis as a means to predict ground surface motions at sites where soft soils overlay the bedrock. While EQTools may be used for professional practice or academic research, the fundamental purpose behind the development of the software is to make available a classroom/laboratory tool that provides a visual basis for learning the principles behind the selection of ground motion histories and their scaling/modification for input into time domain nonlinear (or linear) analysis of structures. EQTools, in association with NONLIN, a Microsoft Windows based application for the dynamic analysis of single- and multi-degree-of-freedom structural systems (Charney, 2003), may be used for learning the concepts of earthquake engineering, particularly as related to structural dynamics, damping, ductility, and energy dissipation. / Master of Science

Water distribution systems, electrical power transmission systems, and other civil infrastructure systems are essential to the smooth and stable operation of regional economies. Since the functions of such infrastructure systems often are inter-dependent, the systems sometimes suffer unforeseen functional disruptions. For example, the widespread power outage due to the malfunction of an electric power substation, which occurred in the northeastern United States and parts of Canada in August 2003, interrupted the supply of water to several communities, leading to inconvenience and economic losses. The sequence of such failures leading to widespread outages is referred to as a cascading failure. Assessing the vulnerability of communities to natural and man-made hazards should take the possibility of such failures into account. In seismic risk assessment, the risk to a facility or a building is generally specified by one of two basic approaches: through a probabilistic seismic hazard analysis (PSHA) and a stipulated scenario earthquake (SE). A PSHA has been widely accepted as a basis for design and evaluation of individual buildings, bridges and other facilities. However, the vulnerability assessment of distributed infrastructure facilities requires a model of spatial intensity of earthquake ground motion. Since the ground motions from a PSHA represent an aggregation of earthquakes, they cannot model the spatial variation in intensity. On the other hand, when a SE-based analysis is used, the spatial correlation of seismic intensities must be properly evaluated. This study presents a new methodology for evaluating the functionality of an infrastructure system situated in a region of moderate seismicity considering functional interactions among the systems in the network, cascading failure, and spatial correlation of ground motion. The functional interactions among facilities in the systems are modeled by fault trees, and the impact of cascading failures on serviceability of a networked system is computed by a procedure from the field of operations research known as a shortest path algorithm. The upper and lower bound solutions to spatial correlation of seismic intensities over a region are obtained.