Seismic hazard assessment and development of attenuation relationship for NCR of Delhi

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SEISMIC HAZARD ASSESSMENT AND

DEVELOPMENT OF ATTENUATION RELATIONSHIP FOR NCR OF DELHI

by

GANESH WASUDEO RATHOD DEPARTMENT OF CIVIL ENGINEERING

submitted

in fulfillment of the requirements of the degree of DOCTOR OF PHILOSOPHY

to the

INDIAN INSTITUTE OF TECHNOLOGY DELHI HAUZ KHAS, NEW DELHI — 110016

INDIA

DECEMBER 2011

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TH

5 . 342 (5-4o 23) RAT- 5

Acc. TH .9171 ...

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Dedicated To

My Parents, Family and Teachers

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CERTIFICATE

This is to certify that the thesis entitled, 'Seismic Hazard Assessment and Development of Attenuation Relationship for NCR of Delhi' being submitted by Mr. Ganesh W. Rathod to

the Indian Institute of Technology Delhi for the award of the degree of DOCTOR OF PHILOSOPHY is a record of the bonafide research work carried out by him. Mr. Ganesh W.

Rathod has worked under our supervision for the submission of this thesis, which to our knowledge has reached the requisite standard.

The thesis or any part thereof has not been presented or submitted to any other University or Institute for any degree or diploma.

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Dr. K.K. Gupta Dr. K. Seshagiri Rao

Associate Professor Professor

Department of Civil Engineering Indian Institute of Technology Delhi

Hauz Khas, New Delhi - 110016

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ACKNOWLEDGEMENTS

I would like to express my gratitude to all the people who helped me over the last five-arrd- _-+tatf.years in the work leading to this dissertation.

I express my profound gratitude towards my supervisors, Prof. K. Seshagiri Rao and Dr.

Kaushal Kumar Gupta, Department of Civil Engineering, IIT Delhi for their inspiring guidance, continuous support and constant encouragement both in research and personal life. I really have insufficient words to express my gratitude. Their vast experience in the area and willingness to impart their knowledge has helped me during the period of research. It is because of their tender care and exceptional interest that this thesis could be brought to the present form.

Prof. K. Seshagiri Rao has involved me on many interesting and challenging projects including Stability Assessment and Support Measures for World's Highest Bridge Abutments, Numerical Modelling, Reliability Analysis, many Hydroelectric Power Projects, site investigations for high rise buildings (80 storied) of GIFT project, Geophysical and Seismic Studies that have allowed me to travel, to meet people in the profession, and to gain knowledge and expertise outside the bounds of my dissertation research. I will forever benefit from these experiences. It has been an honour and a privilege to work not only for the great professor, but also great man.

I am grateful for the guidance provided by my Student Research Committee members, Prof.

A.K. Jain, Prof. N.K. Garg and Prof. Y. Nath. I would like to thank Dr. Vasant Matsagar, Dr. J.T.

Shahu, Prof. K.G. Sharma, Dr. R. Ayothiraman, Prof. G.V. Ramana, Dr. B. Manna and Dr. B.M.

Basha and other geotechnical engineering faculty members for their valuable suggestions and discussions. I express my thanks to the former and present Head, Department of Civil Engineering, for providing the departmental facilities.

I express my sincere thanks to Prof. Mukesh Khare for his interest in my research work, advice and the financial support provided to visit Newcastle University, Newcastle upon Tyne, United Kingdom for research interactions.

The discussions and suggestions received from Prof. Andrzej Kijko, University of Pretoria, South Africa for estimation of catalogue completeness and seismicity parameters is gratefully acknowledged.

I am thankful to Mr. P.K. Jain (Chief Engineer, Design) and Mr. P.S. Gupta (Chief Engineer, Execution) of Konkan Railway Corporation Ltd., India for discussions during the Chenab and Anjikhad Bridge site visits and also for providing computational facilities.

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The help provided by staff of the Geotechnical Engineering Division Laboratories especially Mr. Gusain, Mr. Manoj, Mr. Amit, Mr. /6ehlot, and Mr. Munnilal is appreciated. The help extended on personal fronts by civil engineering department staff particularly Mr. Rajveer Aggrawal, Mr. D. Biswas and Mr. Bikram Chand is gratefully acknowledged.

The field geophysical testing was one of the most hectic and tiring job in the present research work which lasts for more than two years. Here I thank Mr. Kailash Kumar (staff member) and Mr. P. Rajendra (MTech student) for their help and being with me on field for testing during the very hot summers and cold winters.

Thanks are due to my friends Dr. Amit Shrivastava and Dr. Sandip Trivedi for always being there whenever I needed them. I express my deep appreciation to the fellow researchers Dr.

Raman Sharma, Dr. Manoj Kumar, Dr. Ajit Pattnaik, Dr. G.H.V.C. Charry, Dr. Sanjay Wakchaure, MY.

Mr. Alex Varughese, Mr. Shailendra Jain, Dr. Ch. Sudheer, R. Maheswaran, Ms. Praneetha, Mr.

Tejas Thaker,

Mr.

Kausar All and Mr. Madhusudan Reddy for their help and discussions. The support extended by my friends Mr. Shantanu Patra and Mr. Sandip K. Saha during the critical stages of this research work is gratefully acknowledged and I am also thankful for their interest and involvement in the technical discussions.

My gratitude's are due to Mrs. K. Sita and Late Mrs. Kiran Gupta for the homely environment they set up among all of us students. It was the second home to me during these fide years of research. We students had lot of fun and enjoyed celebrating most of the Indian festivals at my supervisor's home. I would never forget those joyful moments.

I am most grateful to my family. I express my deepest gratitude's to my parents, wife, brother and sister. I love them with all of my heart. I am thankful to my parents for the principles they instilled in me as a young man and for their continued support, guidance and love for our family. The technical discussions with my brother Dinesh, and care taken by him during the final stages of work has helped me a lot. I also thank my parents-in-law for all their support. It would have been impossible to complete this work without my family's understanding, patience and sacrifices.

Date: 30th December, 2011 Ganesh W. Rathod

(2005CEZ8222)

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ABSTRACT

Seismic hazard assessment has an important societal impact in describing levels of ground motions to be expected in a given region in the future. In recent years, the interest of the scientific community regarding seismology and seismotectonic has greatly increased, especially in the field related to seismic risk assessment of urban seismic areas and its possible reduction. Challenges in seismic hazard assessment are closely associated with the fact that different regions, due to their differences in seismotectonic setting and earthquake occurrence as well as socio-economic conditions, require different approaches. India's high earthquake risk and vulnerability is evident from the fact that about 59 percent of India's land area could face moderate to severe earthquakes. North India and particularly the Himalayan belt has experienced many strong to moderate earthquakes since 18th century.

Some of the major earthquakes in past are having the magnitude more than 7.0 M. The present thesis focuses the seismic hazard in National Capital Region (NCR) of Delhi, India. For the very purpose of achieving the goal of the study and the high seismic risk posed by the region, NCR of Delhi is selected as a study area. The study area i.e. NCR of Delhi has a population more than 28 million according to 2011 census, located on the banks of river Yamuna. Being the capital of India, the city is considered as highly important viewing to social and economical issues, comes under seismic zone IV according to seismic zonation map of India (BIS:1893-2002), and thereby specifying basic peak ground acceleration (PGA) of 0.24g. The region is located near the highly active Himalayan seismic belt, in addition to that there are many near field seismic sources which would generate significant hazard in the region.

With this point of view, a detailed study has been attempted in the present work to propose the present seismic hazard scenario for NCR of Delhi at bedrock level in terms of Peak Ground Acceleration (PGA) using state of art Probabilistic Seismic Hazard Analysis

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(PSHA) and Deterministic Seismic Hazard Analysis (DSHA) and then at ground surface level using 1-0 seismic site response analysis.

Starting from the preparation of a new seismotectonic map of the study area considering 360 km radius around the city, which consist of the seismogenic sources, past earthquake data collected from various sources and available literature, the completeness of the data has been evaluated using Cumulative Visual Interpretation (Tinti and Mulargia, 1985), Stepp (1973) method and Maximum Likelihood technique (Kijko and Sellevoll, 1989, 1992). The data has been then analyzed statistically and recurrence relationships has been obtained using G-R method (Gutenberg and Richter, 1944).

In the dearth of recorded ground motion data, stochastic seismological modelling has been adopted for generation of synthetic ground motions. The recorded earthquake data of Uttarkashi earthquake of 20th October, 1991 and Chamoli earthquake of 28th March, 1999 are used to estimate the source parameters and to calibrate the seismological model. This synthetically generated ground motion data is then used to develop the attenuation relationship. The proposed attenuation relationship for estimation of PGA at bedrock is given as:

logio

(PGA) = c, + c2(M„, — 6) + c3(Mw

— 6)2 +

c4(R)+

c5 logio (R)+ logio (e)

₍₁₎

where, PGA is the geometric mean of the horizontal PGA values in units of g; M„, is the moment magnitude; R=1/(D24-H2), R is the hypocentral distance in km, D= Depth, H= Nearest fault distance; E is a random error. The regression coefficients and error are estimated as:

cl= 0.66845, c2= 0.49908, c3= -0.04665, c4= -0.00257, c5= -2.303x0.37329 and standard deviation of random error cr(logio e). 0.1118.

The proposed attenuation relationship is for the NCR of Delhi and the Himalayan region which can be extended for estimation of seismic hazard in North India also. The proposed

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attenuation relationship is validated against the recorded earthquake data and compared with the other attenuation relationships of various region.

The deterministic and probabilistic seismic hazard analyses are performed for the study area for estimation of bedrock level PGA. The probabilistic approach is used to estimate PGA models at bedrock level corresponding to return period of 475, 950, 2475 and 4950 years.

The spatial variation in estimated bedrock PGA values are captured and PGA maps at various return periods are prepared. Results have been compared with various studies reported in the literature and also with the Indian Standard Code of practice.

In the next part of thesis, detailed geophysical site characterization has been attempted by in-situ measurement of shear wave velocity (Vs) and primary wave velocity (Vp) at 210 test locations in the study region by Multi Channel Analysis of Surface Waves (MASW) and Seismic Refraction (SR) testing using 48 channel seismograph. Vs and Vp maps are prepared at every 1.5 m depth. The average shear wave velocity up to depth of 30 m (\ism) is also calculated, which is ranging from 188 to 836 m/s for Delhi region. The seismic site characterization of the study area has been carried out and five zones (ZA, ZB, ZC, ZD and ZE) of similar dynamic properties, geological and geotechnical units are defined. The ranges of Vs and V, values at all depths and Vs30 values for each zone are given in Table 1. According to NEHRP classification, the study area falls under class C and D.

Table 1. Range of Vp, V5 and Vs30 Values for the Proposed Site Classification

Zones ZA ZB ZC ZD ZE

Vp (m/s) 410-2080 400-1780 320-1600 300-1120 300-850 Vs (m/s) 260-1210 160-850 130-700 140-520 120-380

Vs30 501-836 381-490 300-378 260-299 188-259

More than 3500 borehole data is collected and synthesized to assess the geotechnical properties. Based on this dataset, empirical equations among various properties are

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proposed for the region. A systematic comparison with the available literature supported by error analysis is also presented.

Assessments of local site conditions and earthquake motion characteristics at the ground surface play a key role in determination of local site effects in geotechnical engineering practice. Local site effects are often expressed in terms of the resonance or fundamental frequency, spectral amplification and vulnerability index (Nakamura; 1996, 1997) which depends on soil condition and bedrock depth. The Nakamura (1989) method has proved to be the most convenient technique to estimate fundamental frequencies of soft deposits. From this perspective, single point ambient vibration (also referred as microtremors or seismic noise) measurements are performed at 210 locations in study area, and a classification is also proposed with five categories (F1, F2, F3, F4 and F5). The proposed classification is based on the shape of the FIN spectra, predominant frequency and vulnerability index. The proposed classification is presented in Table 2.

Since the average shear wave velocity up to 30 m depth (V530) is also available from the MASW tests, it is observed that Vs30 is high at places with high resonance frequency and vice versa. A correlation between Vs30 and predominant frequency is also developed for study area as given below:

Vs30 = 289.08

f °13

⁽²⁾

This correlation will be useful in estimating the Vs30 for the locations in and around Delhi.

Thus, Nakamura method can be used as a very quick and reliable method for estimating local site effects leading to a seismic microzonation of the whole region.

Seismic site response analysis is required to determine the response of ground to the motion of the bedrock and also determining the effect of local soil conditions on amplification of seismic waves and hence estimating the free field response spectra for future design purposes. the probabilistic procedures are proposed in the present study for

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Tablet. Fundamental Frequency and Vulnerability Index Along with Soil Type for Each Classification Type

Proposed Fundamental Vulnerability

Classification Soil Type

Frequency Index Zone Silty sand with gravel, kankar

Fl deposits/Weathered Quartzite > 5.0 Hz <5.0 ZA, ZB (High 'N' value)

F2 ^DenseSandy silt and Silty sand

With high 'N' value 3.0 —5.0 Hz 5.0 to 10.0 ZB, ZC Sandy silt and Silty sand with

F3 seams of clay (Older alluvium: 2.0 —3.0 Hz 10.0 to 15.0 ZC Pleistocene)

F4 Sandy silt and Silty sand with low

'N' value 1.0 —2.0 Hz 15.0 to 20.0 ZD Sandy silt and Silty sand with low

F5 'N' value (Newer alluvium: < 1.0 Hz > 20.0 ZD, ZE Holocene)

consideration of the uncertainties in various input parameters required for site response analysis. Stochastic 1D seismic site response analysis is attempted in the present study and parametric study has been performed. The uncertainties in input ground motion, shear wave velocity and non linear soil properties are modelled in the analyses using Monte Carlo simulations. The influence of input ground motion selection, variation in shear wave velocity (i.e. _{aln Vs),}number of samples used, variation in shear modulus reduction and damping curves (i.e. variation in nonlinear properties) and effect of individual layer thickness are investigated through parametric study using stochastic seismic site response analysis.

The stochastic 1D site response analyses are then applied to the various site classes (A, B, C, D and E) of NCR of Delhi. The acceleration response spectra at surface for site class A, B, C, D and E are compared with BIS:1893-2002. The results are then compared with microtremor findings also, which are in good agreement with each other.

Considering the seismic status and varied geological formation of study area, there is a great need for the assessment of liquefaction potential. The uncemented, saturated sand/silts are considered to be highly susceptible to liquefaction. Andrus et al. (2004a) reported that the Pleistocene soils are also prone to liquefaction and an aging factor was

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proposed by them and the same has been adopted in the present liquefaction analysis. The liquefaction potential of study region is evaluated using the SPT 'N' value based method by Idriss and Boulanger (2010) and shear wave velocity (V5) based method by Andrus and Stokoe (2000) and Andrus et al. (2004a). The liquefaction hazard maps with respect to factor of safety from all the three methods used are prepared. These maps will help in designing the foundation system of a structure, life line structures, design of roads and reducing the risk from liquefaction through appropriate mitigation.

Based on these detailed studies, the present seismic hazard scenario of NCR of Delhi is proposed and discussed. In the present study an attempt has been made to touch every aspect required for the seismic hazard assessment of a region. Starting from the collection of earthquake data, its processing, catalogue preparation, seismological modelling in the absence of recorded ground motion data, development of attenuation relationship, geophysical and geotechnical characterization, a process for ground response analysis and liquefaction potential assessment are discussed in detail in the present research work. In combination, the studies presented here address some of the key issues associated with seismic hazard assessment and its probable solution. The present work can hopefully serve as a basis for further investigations in the future.

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2.3.2.1.1 Local magnitude (Richter scale), ML (Richter, 1935) 27 2.3.2.1.2 Surface wave magnitude, M5 (Gutenberg, 1945a) 27 2.3.2.1.3 JMA (Japanese Meteorological Agency) magnitude, MJMA 28 2.3.2.1.4 Kawasumi magnitude, Mk (Kawasumi, 1951) 28 2.3.2.1.5 Body wave magnitude, mb (Gutenberg, 1945b; 1945c) 28

2.3.2.1.6 Duration magnitude, Md 29

2.3.2.1.7 Earthquake energy, E (erg = 10-7J) 29

2.3.2.1.8 Moment magnitude, Mw 29

2.3.2.2 Earthquake intensity 30

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2.3.3 Parameters of Engineering Interest 32

2.4 Seismic Wave Propagation 33

2.4.1 Elastic Moduli 33

2.4.2 Body Waves and Surface Waves 34

2.5 Ground Motion Parameters 35

2.5.1 Amplitude Parameters 36

2.5.1.1 Peak acceleration 36

2.5.1.2 Peak horizontal velocity 37

2.5.1.3 Peak displacement 37

2.5.2 Frequency Parameters 38

2.5.3 Duration Parameters 40

2.5.3.1 Definitions of distance terms of earthquake 42 2.5.4 Estimation of Ground Motion Parameters 43 2.6 Earthquake Catalogue and Attenuation Relationships 50

2.7 Site Characterization 51

2.7.1 Geological Details 52

2.7.2 Geotechnical Investigations 52

2.7.3 Geophysical Investigations 55

2.8 Local Site Effects 59

2.8.1 Methods of Estimating Local Site Effects 60

2.8.1.1 Empirical methods 60

2.8.1.1.1 Based on geology and intensity 61 2.8.1.1.2 Based on geology and amplification 61 2.8.1.1.3 Based on geotechnical parameters and amplification 63 2.8.1.1.4 Based on surface geology and response spectrum 65

2.8.1.1.5 Based on surface topography 66

2.8.1.2 Experimental methods 69

2.8.1.2.1 Microtremor data 69

2.8.1.2.2 Weak motion data 73

2.8.1.2.3 Strong motion data 75

2.8.1.3 Numerical methods 76

2.9 Seismic Site Response Analysis 76

2.9.1 Simplified (Empirical) Analysis 78

2.9.2 Equivalent-Linear Model 83

2.9.2.1 Linear elastic wave propagation 88

2.9.2.2 Equivalent-linear analysis 92

2.9.3 Nonlinear Models 96

2.9.3.1 Mathematical representations of soil column and solution routines 96

2.9.3.2 Soil material models 97

2.9.3.3 Viscous damping formulations 101

2.9.4 Summary of Specific Nonlinear Codes 102

2.9.4.1 SHAKE-04 102

2.9.4.2 DEEPSOIL 102

2.9.4.3 D-MOD_2 103

2.9.4.4 TESS 104

2.9.4.5 OpenSees 104

2.9.4.6 SUMDES 105

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2.9.5 Selection of Representative Time Histories 105

2.10 Seismic Hazard Analysis 107

2.10.1 Deterministic Seismic Hazard Analysis 109 2.10.2 Probabilistic Seismic Hazard Analysis 112 2.10.3 Summary of Strengths and Limitations of DSHA and PSHA 113

2.10.3.1 DSHA 113

2.10.3.2 PSHA 114

2.11 Liquefaction Potential Assessment 116

2.11.1 Mechanism of Liquefaction 117

2.11.2 Factors Affecting Soil Liquefaction 120 2.11.3 Evaluation of Liquefaction Potential 121

2.11.3.1 Field methods 126

2.11.3.1.1 SPT based methods 127

2.11.3.1.2 CPT based method 132

2.11.3.1.3 Shear wave velocity (Vs) based methods 135

2.11.3.2 Laboratory methods 139

2.11.3.2.1 Cyclic triaxial test 139

2.11.3.2.2 Cyclic direct simple shear test 140 2.11.3.2.3 Cyclic torsional shear test 140

2.11.3.2.4 Shake table test 141

2.11.3.3 Magnitude scaling factor 141

2.11.3.3.1 Seed and Idriss (1982) scaling factor 143 2.11.3.3.2 Ambraseys (1988) scaling factor 143 2.11.3.3.3 Arango (1996) scaling factors 143 2.11.3.3.4 Andrus and Stokoe (1997) scaling factor 144 2.11.3.3.5 Youd and Noble (1997a) scaling factor 144 2.12 Overview of Seismic Hazard Studies in Past 145 2.12.1 Seismic Studies all Over the World 146 2.12.2 Seismic Zonation Efforts in India by BIS 146

2.12.3 Seismic Studies in India 148

2.13 Summary 151

2.14 Conclusions 153

Chapter 3 GENERAL GEOLOGICAL, GEOTECHNICAL AND TECTONIC SETTING 157

3.1 General 157

3.2 Recent Seismic Activity in the Region 157

3.3 Delhi Fold Belt 159

3.4 General Geology of the Area 160

3.5 Geotechnical Characteristics 165

3.5.1 Collection and Organization of the Data 165

3.5.2 Detailed Soil Profiles 166

3.5.3 Grain Size Distribution (GSD) Curves 169

3.5.4 Characteristics of Delhi Quartzite 178

3.5.5 Geochemical and Mineralogical Analysis 181 3.5.5.1 Petrography

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3.5.5.2 XRD-mineralogy 182

3.5.5.3 SEM Analysis 182

3.5.6 Ground Water Contours 183

3.5.7 Bedrock Depths 187

3.6 Tectonic Setting of the Region 188

3.6.1 Fault Map 191

Chapter 4 EARTHQUAKE CATALOGUE AND RECURRENCE RELATIONSHIPS 199

4.1 General 199

4.2 Catalogue Studies Attempted in the Past for India 200

4.3 Catalogue Compilation 201

4.3.1 Pre-historical and Historical Database 202

4.3.2 Consistency in Magnitude 203

4.3.3 Declustering of Catalogue 205

4.3.3.1 Declustering Algorithms 208

4.3.3.2 Results of Declustering 214

4.4 Generation of a Seismotectonic Map 215 4.5 Completeness Analysis of Catalogue 216 4.5.1 Cumulative Visual Interpretation (CUVI) Method 218

4.5.2 Stepp (1973) Method 222

4.5.3 Kijko and Sellevoll (1989, 1992) Method 230 4.6 Frequency-Magnitude Recurrence Relationship 233

4.7 Maximum Possible Earthquake 236

Chapter 5 DEVELOPMENT OF SEISMIC ATTENUATION RELATIONSHIP 239

5.1 General 239

5.2 Seismicity 240

5.2.1 Seismic Network 241

5.3 Seismological Model 241

5.3.1 EXSIM: Extended Earthquake Fault Simulation Program 248 5.3.2 Seismological Modelling and Attenuation Relations 249

5.4 Model Parameters for Simulations 250

5.4.1 Attenuation of Fourier Amplitudes with Distance 251

5.4.2 Kappa Factor 252

5.4.3 Duration of Ground Motion 252

5.4.4 Regional Shear Wave Velocity and Density 254

5.4.5 Source Parameters and Calibration 254

5.5 Simulation of Acceleration Time Series 259 5.6 Types of Ground Motion Prediction Equations 262 5.7 Attenuation Relationship and Regression Method 267

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5.7.1 Validation and Comparison with Attenuation Relations of Other Regions 274

Chapter 6 DETERMINISTIC AND PROBABILISTIC SEISMIC HAZARD ANALYSIS 281

6.1 General 281

6.2 Deterministic Seismic Hazard Analysis 282

6.3 Regional Recurrence Relationships 290

6.4 Deaggregation Analysis 290

6.5 Probabilistic Seismic Hazard Analysis 294

6.5.1 Theoretical Framework 296

6.5.2 Estimation of Peak Ground Acceleration 298

6.6 Summary 306

Chapter 7 SITE CHARACTERIZATION THROUGH GEOPHYSICAL TESTING 307

7.1 General 307

7.2 Geophysical Methods 308

7.2.1 Seismic Reflection 309

7.2.2 Seismic Refraction 311

7.2.3 Spectral Analysis of Surface Waves (SASW) 314 7.2.4 Multi-channel Analysis of Surface Waves (MASW) 315

7.3 Details of Equipment 316

7.3.1 48 Channel Engineering Seismograph 317

7.3.2 Geophones 318

7.3.3 Geophone Cables 321

7.3.4 Source Generators 321

7.3.4.1 Sledge Hammer 322

7.3.4.2 PEG-40 322

7.4 Seismic Refraction Test 323

7.4.1 Field Testing Program 324

7.4.2 Data Acquisition 325

7.4.3 Analysis of the Data 326

7.5 Multi Channel Analysis of Surface Wave Testing 344

7.5.1 Field Testing Program 344

7.5.2 Data Acquisition 345

7.5.3 Analysis of the Data 349

7.6 Seismic Site Characterization 365

7.6.1 Average Shear Wave Velocity ( Vs30 ) 365

7.6.2 Proposed Site Classification 372

7.6.2.1 NEHRP Zonation Map 376

7.7 Development of Empirical Correlations 378

7.7.1 Development of Data Set 378

7.7.2 Empirical Correlation Between Vs and SPT 'N' 379 7.7.3 Adequacy of the Proposed Empirical Correlation 381

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7.7.3.1 Comparing Measured and Predicted Vs 381

7.7.3.2 Graphical Residual Analysis 382

7.7.3.3 Normalized Consistency Ratio, Cd 383 7.7.3.4 Comparative Study with the Available Correlations 384

7.8 Results and Discussion 386

Chapter 8 LOCAL SITE EFFECTS USING AMBIENT VIBRATION MEASUREMENTS 389

8.1 General 389

8.2 Nakamura H/V Ratio Method 390

8.3 Field Testing Program 395

8.4 Data Acquisition 396

8.5 Analysis of the Data 400

8.6 Proposed Classification 402

8.6.1 Frequency Zone Fl 409

8.6.2 Frequency Zone F2 415

8.7 Vulnerability Index (Kg) 418

Chapter 9 SEISMIC SITE RESPONSE ANALYSIS 423

9.1 General 423

9.2 Background for Uncertainty Modelling and Parametric Study 424

9.3 Proposed Methodology 431

9.4 Stochastic Analysis 433

9.5 Monte Carlo Simulation 433

9.5.1 Variability of the Input Parameters 435

9.6 Selection of Input Motion 437

9.7 Soil Property Variability 442

9.7.1 Shear Wave Velocity Profile 443

9.7.2 Nonlinear Soil Properties 446

9.8 Parametric Study 450

9.8.1 Influence of Input Ground Motion Selection 450 9.8.2 Influence of Shear Wave Velocity Variation 456 9.8.3 Influence of Number of Samples of Shear Wave Velocity 457

9.8.4 Influence of Soil Nonlinearity 462

9.8.5 Influence of Individual Layer Thickness 465

9.8.6 Summary of Parametric Study 470

9.9 Case Study 471

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Chapter 10 LIQUEFACTION POTENTIAL ASSESSMENT 479

10.1 General 479

10.2 Liquefaction Potential and Analysis 480

10.3 SPT Based Methods 486

10.3.1 Idriss and Boulanger (2010) Method 487 10.3.1.1 Components of the stress-based framework 487 10.3.1.2 Summary of the Idriss-Boulanger procedure 492

10.4 Shear Wave Velocity Based Methods 502

10.4.1 Andrus and Stokoe (2000) Method 503

10.4.2 Andrus et al. (2004a) Method 511

Chapter 11 SUMMARY AND CONCLUSIONS 519

11.1 General 519

11.2 Geological, Geotechnical and Seismotectonic Characteristics 520 11.3 Earthquake Catalogue and Recurrence Relationships 523

11.4 Attenuation Relationship 524

11.5 Deterministic and Probabilistic Seismic Hazard Analysis 525 11.6 Site Characterization Through Geophysical Testing 526

11.6.1 Seismic Refraction Tests 527

11.6.2 MASW Tests 528

11.7 Local Site Effects using Ambient Vibration Measurements 528

11.8 Seismic Site Response Analysis 530

11.9 Liquefaction Potential Assessment 533

11.10 Limitations and Suggestions 535

REFERENCES 537

Appendix A Goodness of Fit (GOO Tests 587

Appendix B Composite Earthquake Catalogue 595

Appendix C Hazard Curves 615

Appendix D One Dimensional Velocity Models 643

Appendix E Two Dimensional Vp Models 659

Appendix F Two Dimensional Vs Models 683

Appendix G Seismic Site Response Analysis 707

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Appendix H Liquefaction Potential Analysis Using SPT Based Method 749 Appendix I Liquefaction Potential Analysis Using Vs Based Methods 779

VITAE 835

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Seismic hazard assessment and development of attenuation relationship for NCR of Delhi