Fundamentals of Soil Dynamics and Earthquake Engineering

Description

This textbook presents the fundamentals of Soil Dynamics, combined with the basic principles, theories and methods of Geotechnical Earthquake Engineering. It is designed for senior undergraduate and postgraduate students in Civil Engineering & Architecture. The text will also be useful to young faculty members, practising engineers and consultants. Besides, teachers will find it a useful reference for preparation of lectures and for designing short courses in Soil Dynamics and Geotechnical Earthquake Engineering. The book first presents the theory of vibrations and dynamics of elastic system as well as the fundamentals of engineering seismology. With this background, the readers are introduced to the characteristics of Strong Ground Motion, and Deterministic and Probabilistic seismic hazard analysis. The risk analysis and the reliability process of geotechnical engineering are presented in detail. An in-depth study of dynamic soil properties and the methods of their determination provide the basics to tackle the dynamic soil structure interaction problems. Practical problems of dynamics of beam foundation systems, dynamics of retaining walls, dynamic earth pressure theory, wave propagation and liquefaction of soil are treated in detail with illustrative examples. Title Fundamentals of Soil Dynamics and Earthquake Engineering Copyright Dedication CONTENTS Preface 1. INTRODUCTION 1.1 Geotechnical Engineering and Soil Dynamics 1.2 Soil Dynamics and Structural Dynamics 1.3 Dynamic Loading and Dynamics of Vibrations 1.4 Stress Conditions of Soil under Dynamic Loading 1.5 Soil Dynamics and Earthquake Engineering 1.6 Lithological and Seismotectonics Profile of India 1.7 Some Past Indian Earthquakes 1.7.1 The Bhuj Earthquake 2001 1.7.2 The Assam Earthquake 1897 1.7.3 The Bihar–Nepal Earthquake 1934 1.8 Other Earthquakes of India 1.8.1 Some Past Indian Earthquakes 1.9 Global International Seismicity—Seismicity of the Earth 1.9.1 Global Seismic Hazard Assessment 1.10 Significant Case History of Some Past Earthquakes 1.10.1 San Francisco, California, Earthquake (April 18, 1906 1.10.2 Loma Prieta Earthquake, Part 1 1.10.3 Loma Prieta Earthquake, Part 2 1.10.4 San Fernando Valley California Earthquakes 1.10.5 Great Hanshin-Awaji (Kobe) Earthquake, January 17, 1995 1.10.6 Izmit (Kocaeli) Turkey Earthquake, August 17, 1999-Set 1, Coastal Effects 1.10.7 Duzce, Turkey Earthquake, November 12, 1999 1.10.8 Great Chile Earthquake of May 22, 1960 1.11 Uncertainty, Hazard, Risk, Reliability and Probability of Earthquakes 1.11.1 Uncertainty and Hazard 1.11.2 Risk, Reliability and Probability of Earthquakes 1.12 Earthquake Prediction and Prevention Problems 2. SEISMOLOGY AND EARTHQUAKES 2.1 Introduction 2.2 Structure of the Earth’s Interior 2.2.1 Rheological Division of the Earth’s Interior 2.3 Continental Drifts 2.3.1 The Mobile Belt 2.3.2 The Gondwanaland Group 2.3.3 Occurrence of Distribution 2.3.4 The Himalayas 2.4 Plate Tectonics 2.5 Elastic Rebound Theory 2.6 Reservoir Triggered Seismicity 2.6.1 Mechanism of RTS Earthquakes 2.7 Mechanics of Faulting and Earthquakes 2.8 Size of Earthquake 2.8.1 Intensity of Earthquake 2.8.2 Magnitude of Earthquake 2.8.3 Energy Associated with Earthquake 2.9 Locating the Earthquakes 2.9.1 Location of the Epicentre 2.9.2 Determining the Depth of Focus of Earthquake 2.9.3 Isoseismal Maps 2.10 Plate Tectonics, Plate Boundaries and Earthquakes in India 2.10.1 Earthquakes in Peninsular India 2.10.2 Earthquake in Himalayan Region 2.10.3 Earthquakes in the North-Eastern Region 2.10.4 Earthquakes in Andaman and Nicobar Islands 2.11 Measuring Earthquakes Problems 3. THEORY OF VIBRATIONS 3.1 Introduction 3.2 Periodic Motion 3.2.1 Frequency Analysis 3.3 Classical Theory 3.4 Free Vibrations SDF Undamped System 3.5 Free Vibrations SDF Damped System 3.5.1 Free Vibrations of Viscously Damped System 3.6 Forced Vibration—SDF Undamped System 3.7 Forced Vibration—SDF Damped System 3.8 Energy Dissipation Mechanism—Types of Damping 3.9 System under Impulse and Transient Loading 3.9.1 Method of Solution 3.9.2 Duhamel’s Integral 3.9.3 Dirac Delta Function 3.10 Transmissibility 3.10.1 Transfer Function 3.11 Fourier Analysis 3.12 Rotational and Torsional Vibration 3.13 Mobility and Impedance Methods 3.14 Analogue Method 3.14.1 Dimensional Analysis 3.15 Nonlinear Vibrations 3.16 Random Vibrations Problems 4. DYNAMICS OF ELASTIC SYSTEM 4.1 Introduction 4.2 Vibrations of Two-Degree Freedom System 4.2.1 Free Vibrations 4.2.2 Damped Vibrations 4.3 Vibrations of Multi-Degree Freedom System 4.4 Mode Participation Factor 4.5 Vibrations of Continuous Systems 4.6 Vibrations of Beams 4.7 Vibrations of Beams on Elastic Foundation 4.8 Vibration of Plates 4.9 Vlasov and Leontev Method for Vibration Analysis 4.9.1 Free Vibrations of Beams on Elastic Foundation 4.10 Vibration of Plates on Elastic Foundation 4.11 Numerical Methods 4.12 Dimensional Analysis 4.13 Analogue Method Problems 5. WAVE PROPAGATION 5.1 Introduction 5.2 One-Dimensional Wave Motion 5.3 Axial Wave Propagation 5.4 Solution of Wave Equation 5.5 Wave Propagation in an Elastic Infinite Medium 5.5.1 2D Stress Analysis 5.5.2 3D Stress Alalysis 5.5.3 Solution for Equation of Motion—Primary Wave 5.5.4 Solution for Equation of Motions—Shear Waves 5.6 Lamb Theory for Wave Propagation 5.7 Rayleigh Waves—Wave Propagation in Elastic Half Space 5.7.1 Mechanism of Wave Propagation at the Surface 5.7.2 Love Waves 5.8 Concepts of Phase Velocity and Group Velocity 5.8.1 Phase Velocity 5.8.2 Group Velocity 5.8.3 Relationship of Group Velocity with Phase Velocity 5.9 Propagation of Flexural Waves in Beams on Elastic Foundations 5.9.1 Equation of Wave Motion Problems 6. DYNAMIC SOIL PROPERTIES 6.1 Introduction 6.2 Representation of Stress Condition by Mohr’ Circle and Stress Path 6.3 Dynamic Stress-Strain Relationship 6.4 Determination of Dynamic Soil Properties 6.4.1 Field Tests 6.4.2 Laboratory Tests 6.4.3 Interpretation of Test Results 6.5 Shake Table Testing 6.6 Shear Phenomenon of Particulate Media 6.7 Behaviour of Soil under Pulsating Load 6.8 Damping Ratio Problems 7. DYNAMIC EARTH PRESSURE 7.1 Introduction 7.2 Classical Theory for Static Earth Pressure 7.2.1 Rankine’s Earth Pressure Theory 7.2.2 Coulomb’s Earth Pressure Theory 7.2.3 Culmann’s Graphical Construction 7.3 Dynamic Earth Pressure Theory 7.4 Mononobe-Okabe Theory for Dynamic Earth Pressure 7.4.1 Yield Acceleration 7.5 Displacement Analysis 7.6 Dynamic Stability Analysis 7.6.1 Effect of Saturation on Lateral Earth Pressure 7.6.2 Partially Submerged Backfill 7.7 Recommendations of Indian Standard Code of Practice 7.7.1 Lateral Earth Pressure 7.7.2 Dynamic Active Earth Pressure 7.7.3 Dynamic Passive Earth Pressure 7.7.4 Active Pressure Due to Uniform Surcharge 7.7.5 Passive Pressure to Uniform Surcharge Problems 8. STRONG GROUND MOTION 8.1 Introduction 8.2 Strong-Motion Observations Studies 8.3 Strong-Motion Measurement 8.3.1 Seismographs 8.3.2 Other Types of Seismograms 8.3.3 Data and Digitization 8.3.4 Strong-Motion Records 8.4 Array Observations 8.4.1 Array Observations in Japan and USA 8.5 Characteristic of Strong Ground Motion 8.5.1 Earthquake Magnitude 8.5.2 Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV), Peak Ground Displacement (PGD 8.5.3 Duration of the Strong Ground Motion 8.5.4 Ground Motion Attenuation Model 8.5.5 Regression Analysis 8.5.6 Stress Drop 8.6 Strong-Motion Parameters and Its Evaluation 8.6.1 Frequency Content Parameters 8.6.2 Power Spectra 8.6.3 Bandwidth and Predominant Period 8.6.4 Spectral Parameters 8.6.5 Other Ground-Motion Parameters 8.6.6 Corner Frequency and Cut-off Frequency 8.7 Evaluation of Strong-Motion Parameters 8.8 Method for Simulating Strong Ground Motion Problems 9. SEISMIC HAZARD ANALYSIS 9.1 Introduction 9.2 Meaning of Earthquake-Hazard Analysis 9.3 Parameters for Seismic Hazard Assessment 9.3.1 Evaluation of Seismic Source 9.3.2 Ground Motion Attenuations 9.3.3 Earthquake Recurrence Analysis 9.3.4 Local Site and Soil Conditions 9.4 Risk Index and Evaluation of Earthquake Motion 9.4.1 Historical Earthquake Data 9.4.2 Aleratory and Epistemic Variability 9.4.3 Logic Tree 9.4.4 Active-Fault Data 9.4.5 Evaluation of Probability of Earthquake Occurrence Based on Historical Earthquake Data 9.4.6 Calculation of Earthquake Occurrence Based on Active-Fault Data 9.4.7 Considerations of Combined Historical Earthquake Data and Active-Fault Data 9.5 Method of Analysis 9.5.1 Deterministic Seismic Hazard Analysis (DSHA 9.5.2 Probabilistic Seismic Hazard Analysis (PSHA 9.6 Classification of Seismic Zones 9.6.1 Parameters for Seismic Zoning 9.6.2 Seismic Zoning of India 9.6.3 Seismic Zoning Maps of Indian Code 9.6.4 Seismic Zoning Maps by Individual Studies 9.6.5 Zoning Maps Based on Probabilistic Approach 9.7 Model for Evaluation of Seismic Hazard 9.7.1 Poisson Model 9.7.2 Non-Poisson Model 9.7.3 Other Models 9.7.4 Seismic Hazard Analysis Based on Poisson Model Problems 10. LIQUEFACTION OF SOILS 10.1 Introduction 10.2 Theory of Liquefaction 10.3 Liquefaction Analysis 10.3.1 Cyclic Resistance Ratio 10.4 Factor of Safety against Liquefaction 10.5 Factors Responsible for Liquefaction 10.6 Criterion for Assessing Liquefaction 10.6.1 Criteria Based on Grain Size 10.6.2 Energy Based Liquefaction Criterion 10.7 Evaluation of Liquefaction Potential 10.8 Laboratory Investigations of Soil Liquefaction 10.8.1 Laboratory Test Data 10.9 Mechanics of Dynamic Compaction 10.10 Advances in the Analysis of Soil Liquefaction 10.10.1 Effective Stress Method for Liquefaction Analysis 10.10.2 Liquefaction Analysis Based on Material Instability 10.11 Remedial Measures for Liquefaction Problems 11. RISK, RELIABILITY AND VULNERABILITY ANALYSIS 11.1 Introduction 11.2 Reliability and Probability of Failure 11.3 Reliability and Geotechnical Engineering 11.4 Uncertainty in Soil Strength 11.4.1 Variation of Strength Parameters of Soil 11.5 General Principles of Reliability 11.6 Reliability and Distribution Function 11.6.1 Normal Distribution Function 11.6.2 Lognormal Distribution 11.6.3 Beta Distribution Function 11.7 Risk and Reliability 11.7.1 Risk Analysis 11.7.2 The Role of Acceptable Risk 11.7.3 Risk 11.7.4 Decision Rules 11.7.5 Risk Assessment 11.7.6 Common Consequence Analysis 11.8 Vulnerability Analysis 11.9 Damage and Loss Estimation Problems APPENDIX: VIBRATION MEASUREMENTS A.1 Introduction A.2 General Considerations for Measurements A.3 Principle of Vibration Measurement A.4 Vibration Measurement for Earthquakes A.5 Vibration Instruments A.5.1 Vibration Exciters A.5.2 Instruments with High Natural Frequency A.5.3 Vibration Measuring Devices A.6 Role of Transducers in Instrumentation A.6.1 Seismic Pickups A.7 Sensitivity of Measuring Instruments A.8 Dynamic Testing of Foundations and Structures A.9 Vibration Measurements for Random Signals (Random Vibrations A.9.1 Signal Analysis Techniques A.9.2 Time Domain Analysis A.9.3 Frequency Domain Analysis A.9.4 Transfer Function A.9.5 Amplitude Modulation A.9.6 Frequency Modulation REFERENCES INDEX Back cover