Earthquake Science and Engineering Earthquakes form one of the categories of natural disasters that sometimes result in huge loss of human life as well as destruction of (infra)structures, as experienced dur- ing recent great earthquakes. This book addresses scientific and engineering aspects of earthquakes, which are generally taught and published separately. This book intends to fill the gap between these two fields associated with earthquakes and help seismol- ogists and earthquake engineers better communicate with and understand each other. This will foster the development of new techniques for dealing with various aspects of earthquakes and earthquake-associated issues, to safeguard the security and welfare of societies worldwide. Because this work covers both scientific and engineering aspects in a unified way, it offers a complete overview of earthquakes, their mechanics, their effects on (infra)structures and secondary associated events. As such, this book is aimed at engineering professionals with an earth sciences background (geology, seismology, geophysics) or those with an engineering background (civil, architecture, mining, geological engineering) or with both, and it can also serve as a reference work for academics and (under)graduate students. Earthquake Science and Engineering Ömer Aydan Emeritus Professor, University of the Ryukyus, Okinawa, Japan Cover image: Ömer Aydan First published 2023 by CRC Press/Balkema Schipholweg 107C, 2316 XC Leiden, The Netherlands e-mail: [email protected] www.routledge.com – www.taylorandfrancis.com CRC Press/Balkema is an imprint of the Taylor & Francis Group, an informa business © 2023 Ömer Aydan The right of Ömer Aydan to be identified as author of this work has been asserted in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Although all care is taken to ensure integrity and the quality of this publication and the information herein, no responsibility is assumed by the publishers nor the author for any damage to the property or persons as a result of operation or use of this publication and/ or the information contained herein. Library of Congress Cataloging-in-Publication Data Names: Aydan, Ömer, author. Title: Earthquake science and engineering / Ömer Aydan, Emeritus Professor, University of the Ryukyus, Okinawa, Japan. Description: Boca Raton : CRC Press, Taylor & Francis Group, 2022. | “A Balkema Book.” | Includes bibliographical references and index. Subjects: LCSH: Earthquake engineering. | Seismology. | Earthquake damage. Classification: LCC TA654.6 .A95 2022 (print) | LCC TA654.6 (ebook) | DDC 624.1/762—dc23/eng/20220309 LC record available at https://lccn.loc.gov/2021062703 LC ebook record available at https://lccn.loc.gov/2021062704 ISBN: 978-0-367-75877-6 (hbk) ISBN: 978-0-367-75878-3 (pbk) ISBN: 978-1-003-16437-1 (ebk) DOI: 10.1201/9781003164371 Typeset in Times New Roman by codeMantra Contents Preface xiii Acknowledgements xv About the author xvii 1 Introduction 1 2 Physics of earthquakes 5 2.1 Causes of earthquakes 5 2.2 The stress state of the Earth and the Earth’s crust 8 2.3 The stress state of a fault and its changes during earthquakes 10 2.4 Laboratory experiments 17 2.4.1 Uniaxial compression experiments in relation to earthquakes 17 2.4.2 Stick-slip phenomenon for simple mechanical explanation of earthquakes, and some experiments 19 2.4.2.1 A simple theory of the stick-slip phenomenon 19 2.4.2.2 Device of stick-slip tests 22 2.4.2.3 Stick-slip experiment 23 2.5 Relations between earthquakes and volcanic eruptions 25 2.5.1 Observations 25 2.5.2 Mechanical background of heat emission during crustal deformation 26 2.5.2.1 Fundamental governing equation for energy conservation law 26 2.5.2.2 Temperature distribution in the vicinity of geological active faults 26 2.5.3 Strength reduction due to temperature increase 30 3 Waves and theory of wave propagation 33 3.1 Momentum conservation law 33 3.2 Earthquake-induced waves 34 3.3 Wave propagation in a pond 39 3.4 Wave refraction 39 3.5 Wave propagation through the Earth and inference of the Earth’s interior 43 vi Contents 3.6 Determination of occurrence time 45 3.7 Determination of hypocentre and epicentre 48 3.7.1 Two-dimensional determination of hypocentre and epicentre 48 3.7.2 Three-dimensional determination of hypocentre and epicentre 49 3.7.3 Specific application: the 1998 Adana-Ceyhan earthquake 50 3.8 Determination of magnitude 51 4 Faults and faulting mechanism of earthquakes 55 4.1 Characteristics of earthquake faults 55 4.2 P hysical models on faulting 56 4.2.1 Photo-elasticity tests 56 4.2.1.1 Material properties 56 4.2.1.2 Photo-elasticity tests on the stress state of faults 57 4.2.1.3 Faults with regular asperities 60 4.2.1.4 Faults with irregular rough asperities 61 4.2.1.5 Finite element analyses of fault models 62 4.2.2 Physical model tests 62 4.2.2.1 Experimental device, materials and procedure 62 4.2.2.2 Experiments on granular ground 65 4.3 Characterization of earthquakes from fault ruptures 71 4.3.1 Relation between surface wave magnitude and moment magnitude 71 4.3.2 Relation between MMI and moment magnitude 73 4.3.3 Relation between moment magnitude and rupture length, area and net slip of fault 73 4.4 Inference of faulting mechanism and earthquakes 74 4.4.1 Inference from striations of earthquake faults 74 4.4.2 Inference from wave propagation characteristics 75 5 Strong ground motions and permanent ground deformations 83 5.1 Observations on strong motions and permanent deformations 83 5.1.1 Observations on maximum ground accelerations 83 5.1.2 Permanent ground deformation 83 5.2 Strong motion estimations 86 5.2.1 Empirical approach 86 5.2.2 Green-function-based empirical waveform estimation 91 5.2.3 Numerical approaches 93 5.2.3.1 Finite difference method 94 5.2.3.2 Finite element method 95 5.2.3.3 GPS method 98 5.2.3.4 InSAR method 98 5.2.3.5 EPS method 99 5.2.3.6 Okada’s method 102 5.2.3.7 Numerical methods 103 5.3 Estimations of strong motion parameters from the collapse, failure and slippage of simple structures and simplified reinforced concrete structures 106 Contents vii 5.3.1 Inference of strong motions from masonry walls 106 5.3.2 Inference of strong motions from reinforced concrete structures 108 5.3.3 Inference of strong motions from Mercalli Seismic Intensity 112 6 Vibration analyses of structures 115 6.1 Numerical methods 115 6.2 Simplified analyses of structures for their vibration characteristics 117 6.2.1 Free vibration 118 6.2.2 Damped free vibration 119 6.2.3 Forced vibration subjected to sinusoidal vibration 122 6.2.4 Forced vibration subjected to arbitrary vibration 126 6.3 Measurement techniques for vibration characteristics 128 6.3.1 Free vibration 128 6.3.2 Forced vibration 128 6.3.3 Micro-tremor measurement technique 128 6.4 Fourier spectra analysis 128 6.5 Response spectral analyses 129 6.6 Applications 130 6.6.1 Tower models 130 6.6.2 Building models 133 6.6.3 Photo-elastic frame models and Eigen value analyses by FEM 135 6.6.3.1 Frame only 135 6.6.3.2 Four-story frame models 136 6.6.4 Beam models 139 6.6.5 Tanks 142 6.7 Actual structures 143 6.7.1 Bridge of the University of the Ryukyus 143 6.7.2 Vibration of Yofuke Bridge due to passing trucks 143 6.7.3 Pole for hybrid wind and solar energy 144 6.7.4 Wooden houses 147 6.7.5 Reinforced concrete building 148 6.8 Past studies on the natural frequency of buildings 148 6.9 Dams 150 6.10 Wind turbines 151 6.11 Abandoned mines 152 6.12 Response of Horonobe underground research laboratory during the 2018 June 20 Soya region earthquake and 2018 September 6 Iburi earthquake 153 6.12.1 Characteristics of the Soya region earthquake 153 6.12.2 Characteristics of Iburi earthquake 155 6.12.3 Acceleration records at Horonobe URL 156 6.12.4 Fourier and acceleration response spectra analyses 159 6.12.4.1 Fourier spectra analyses 159 6.12.4.2 Acceleration response spectra analyses 160 6.13 Slopes 161 viii Contents 6.13.1 Characteristics of shaking table 161 6.13.2 Applications to slopes and cliffs 164 6.13.2.1 Model materials 164 6.13.2.2 Testing procedure 166 6.13.3 Model experiments 166 6.13.3.1 Natural frequency of model slopes 166 6.14 Retaining walls 169 6.14.1 Model setup 169 6.14.2 Backfill materials and their properties 170 6.14.3 Shaking table tests on retaining walls with glass beads backfill 172 6.14.4 Shaking table tests on retaining walls with river gravel backfill 172 6.14.5 Shaking table tests on retaining walls with Motobu limestone gravel backfill 175 7 Effects of earthquakes associated surface ruptures on engineering structures 179 7.1 Effects of ground shaking on engineering structures 179 7.1.1 Buildings 179 7.1.1.1 Reinforced concrete buildings 180 7.1.1.2 Masonry buildings 181 7.1.1.3 Timber buildings 181 7.1.1.4 Secondary-type damage in buildings 183 7.1.2 Dams 183 7.1.3 Bridge and viaduct damage 185 7.1.4 Overturning or derailment of vehicles due to ground shaking 187 7.1.5 Tanks 189 7.1.5.1 Classifications of damage to oil tanks 190 7.1.5.2 Damage by the 1995 Kobe earthquake 191 7.1.5.3 Damage by the 1999 Kocaeli earthquake 192 7.1.5.4 The 2001 Kutch earthquake (India) 195 7.1.5.5 The 2003 Tokachi-oki earthquake 198 7.1.6 Sinkholes due to abandoned mines and natural caves 199 7.1.7 Damage to tunnels and underground shelter 201 7.1.7.1 Damage to tunnels 201 7.1.7.2 Damage to the Bukittingi underground shelter 202 7.1.8 Slope failure 204 7.1.8.1 The 1999 Chi-Chi earthquake 204 7.1.8.2 The 2004 Chuetsu earthquake 206 7.1.8.3 The 2005 Kashmir earthquake 206 7.1.8.4 The 2008 Wenchuan earthquake 207 7.1.8.5 The 2008 Iwate-Miyagi intraplate earthquake 210 7.1.9 Embankment failure 211 7.1.10 Retaining-wall failure 212 7.2 Effects of surface ruptures induced by earthquakes on engineering structures 213 7.2.1 Bridges and viaducts 214 7.2.2 Dams 214 Contents ix 7.2.3 Tunnels and subways 215 7.2.4 Slope failures and rockfalls 218 7.2.5 Pylons 220 7.2.6 Linear and tubular structures 220 7.2.7 Buildings 222 7.3 Damage by ground liquefaction and lateral spreading 223 7.4 Effect of rockfalls on built environment 227 8 Seismic design of structures 229 8.1 Fundamental approaches 229 8.2 Seismic design of buildings 237 8.2.1 Framed structures (timber, steel and reinforced concrete structures) 237 8.2.2 Masonry buildings 240 8.2.2.1 Masonry tower or wall (out-of-plane) 240 8.2.2.2 Wall (in-plane) 242 8.2.3 Seismic design of bridges and viaducts 242 8.2.4 Pylons and truss structures 247 8.2.5 Liquid tanks on ground and elevated tanks 253 8.2.5.1 Liquid tanks on ground 253 8.2.5.2 Elevated tanks 254 8.3 Geotechnical structures 256 8.3.1 Seismic design of embankments 256 8.3.1.1 Pseudo-dynamic method 256 8.3.1.2 Dynamic limiting equilibrium method 259 8.3.2 Retaining walls 266 8.3.2.1 Pseudo-dynamic method 266 8.3.2.2 Dynamic limiting equilibrium method 267 8.3.3 Seismic design of slopes 270 8.3.3.1 Cliffs with toe erosion (bending failure) 270 8.3.3.2 Shear and planar failure 273 8.3.3.3 Wedge failure 274 8.3.3.4 Combined shearing and sliding failure 281 8.3.3.5 Flexural toppling failure 282 8.3.3.6 Blocky columnar toppling failure 284 8.3.3.7 Empirical relations between earthquake magnitude and limiting distance for slope failures 285 8.3.3.8 Relation between thoroughgoing discontinuity inclination and slope angle 286 8.4 Seismic design of underground structures 287 8.4.1 Tunnels 288 8.4.1.1 Shallow soil tunnels and conduits 288 8.4.1.2 Shallow underground openings in discontinuous rock mass 290 8.4.1.3 Tunnels in rock mass 291 8.4.2 Rock caverns 292 8.4.3 Underground shelters 292 8.4.4 Tunnels below abandoned mines 294