CONTENTS About the Authors ix Foreword xi Preface and Acknowledgements xiii Introductio xv List of Abbreviations xix List of Symbols xxi 1Earthquake Characteristics 1 1.1 Causes of Earthquakes 1 1.1.1 Plate Tectonics Theory 1 1.1.2 Faulting 6 1.1.3 Seismic Waves 9 1.2 Measuring Earthquakes 14 1.2.1 Intensity 15 7.2.2 Magnitude 18 1.2.3 Intensity-Magnitude Relationships 24 1.3 Source-to-Site Effects 25 1.3.1 Directional Effects 26 1.3.2 Site Effects 27 1.3.3 Dispersion and Incoherence 30 1.4 Effects of Earthquakes 32 1.4.1 Damage to Buildings and Lifelines 34 1.4.2 Effects on the Ground 36 1.4.3 Human and Financial Losses 40 References 44 2Response of Structures 47 2.1 General 47 2.2 Conceptual Framework 47 2.2.1 Definitions 47 2.2.2 Strength-versus Ductility-Based Response 48 2.2.3 Member-versus System-Level Consideration 49 2.2.4 Nature of Seismic Effects 51 2.2.5 Fundamental Response Quantities 53 2.2.6 Social-Economic Limit States 54 2.3 Structural Response Characteristics 56 2.3.1 Stiffness 56 2.3.2 Strength 73 2.3.3 Ductility 85 2.3.4 Overstrength 101 2.3.5 Damping 106 2.3.6 Relationship between Strength, Overstrength and Ductility : Force Reduction Factor 'Supply' 111 References 115 3Earthquake Input Motion 119 3.1 General 119 3.2 Earthquake Occurrence and Return Period 119 3.3 Ground-Motion Models (Attenuation Relationships) 122 3.3.1 Features of Strong-Motion Data for Attenuation Relationships 124 3.3.2 Attenuation Relationship for Europe 125 3.3.3 Attenuation Relationship for Japan 126 3.3.4 Attenuation Relationships for North America 127 3.3.5 Worldwide Attenuation Relationships 128 3.4 Earthquake Spectra 129 3.4.1 Factors Influencing Response Spectra 129 3.4.2 Elastic and Inelastic Spectra 130 3.4.3 Simplified Spectra 137 3.4.4 Force Reduction Factors (Demand) 144 3.4.5 Design Spectra 150 3.4.6 Vertical Component of Ground Motion 152 3.4.7 Vertical Motion Spectra 153 3.5 Earthquake Records 155 3.5.1 Natural Records 155 3.5.2 Artificial Records 159 3.5.3 Records Based on Mathematical Formulations 160 3.5.4 Scaling of Earthquake Records 161 3.6 Duration and Number of Cycles of Earthquake Ground Motions 168 3.7 Use of Earthquake Databases 173 3.8 Software for Deriving Spectra and Generation of Ground-Motion Records 174 3.8.1 Derivation of Earthquake Spectra 175 3.8.2 Generation of Ground-Motion Records 178 References 179 4Response Evaluation 185 4.1 General 185 4.2 Conceptual Framework 185 4.3 Ground Motion and Load Modelling 186 4.4 Seismic Load Combinations 189 4.5 Structural Modelling 191 4.5.1 Materials 194 4.5.2 Sections 200 4.5.3 Components and Systems for Structural Modelling 203 4.5.4 Masses 217 4.6 Methods of Analysis 220 4.6.1 Dynamic Analysis 222 4.6.2 Static Analysis 232 4.6.3 Simplified Code Method 239 4.7 Performance Levels and Objectives 244 4.8 Output for Assessment 249 4.8.1 Actions 250 4.8.2 Deformations 251 4.9 Concluding Remarks 257 References 258 Appendix A - Structural Configurations and Systems for Effective Earthquake Resistance 263 Appendix B - Damage to Structures 291 Index 337