Constitutive Modeling of Soils and Rocks Constitutive Modeling of Soils and Rocks Edited by Pierre-Yves Hicher Jian-Fu Shao First published in France in 2002 by Hermes Science/Lavoisier entitled “Modèles de comportement des sols et des roches Vol.1 et 2” First published in Great Britain and the United States in 2008 by ISTE Ltd and John Wiley & Sons, Inc. Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address: ISTE Ltd John Wiley & Sons, Inc. 6 Fitzroy Square 111 River Street London W1T 5DX Hoboken, NJ 07030 UK USA www.iste.co.uk www.wiley.com © ISTE Ltd, 2008 © LAVOISIER, 2002 The rights of Pierre-Yves Hicher and Jian-Fu Shao to be identified as the authors of this work have been asserted by them in accordance with the Copyright, Designs and Patents Act 1988. Library of Congress Cataloging-in-Publication Data [Modeles de comportement des sols et des roches. English] Constitutive modeling of soils and rocks / Edited by Pierre-Yves Hicher Jian-Fu Shao. p. cm. Includes bibliographical references and index. ISBN 978-1-84821-020-2 1. Engineering geology--Mathematical models. 2. Soil mechanics--Mathematical models. I. Hicher, Pierre-Yves. II. Shao, Jian-Fu. III. Title. TA705.M6113 2008 624.1'51015118--dc22 2007046228 British Library Cataloguing-in-Publication Data A CIP record for this book is available from the British Library ISBN: 978-1-84821-020-2 Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire. Table of Contents Preface to the English Edition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Preface to the French. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Chapter 1. The Main Classes of Constitutive Relations . . . . . . . . . . . . . . . . . 1 Félix DARVE 1.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2. The rheological functional. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3. Incremental formulation of constitutive relations. . . . . . . . . . . . . . . . . . . 5 1.4. Rate-independent materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.4.1. Non-linearity of G and H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.4.2. Anisotropy of G and H. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.4.3. Homogenity of degree 1 of G and H . . . . . . . . . . . . . . . . . . . . . . . . 8 1.5. Notion of tensorial zones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.6. The main classes of rate-independent constitutive relations . . . . . . . . . . 11 1.6.1. Constitutive relations with one tensorial zone. . . . . . . . . . . . . . . . . 11 1.6.2. Constitutive relations with two tensorial zones. . . . . . . . . . . . . . . . 12 1.6.3. Constitutive relations with four tensorial zones. . . . . . . . . . . . . . . . 19 1.6.4. Constitutive relations with n tensorial zones (n > 4) . . . . . . . . . . . . 23 1.6.5. Constitutive relations with an infinite number of tensorial zones . . . 23 1.6.6. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.7. The main constitutive relations for rate-dependent materials. . . . . . . . . . 25 1.7.1. First class of incremental strain decomposition. . . . . . . . . . . . . . . . 25 1.7.2. Second class of incremental strain decomposition. . . . . . . . . . . . . . 26 1.8. General conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1.9. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Chapter 2. Mechanisms of Soil Deformation . . . . . . . . . . . . . . . . . . . . . . . . 31 Jean BIAREZ and Pierre-Yves HICHER 2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.2. Remolded soil behavior. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 vi Constitutive Modeling of Soils and Rocks 2.3. Relationships between discontinuous and continuous medium . . . . . . . . 44 2.3.1. Granular materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 2.3.2. Remolded clayey materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 2.3.3. Granular materials with intergranular glue. . . . . . . . . . . . . . . . . . . 51 2.4. Natural soils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 2.5. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 2.6. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Chapter 3. Elastoplastic Modeling of Soils: Monotonous Loadings. . . . . . . . 77 Philippe MESTAT, Emmanuel BOURGEOIS and Philippe REIFFSTECK 3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 3.2. Elastoplasticity equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 3.2.1. Basic concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 3.2.2. Yield surface and elastic domain. . . . . . . . . . . . . . . . . . . . . . . . . . 79 3.2.3. Plastic flow rule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 3.2.4. Incremental relations for one plastic mechanism model. . . . . . . . . . 81 3.2.5. Incremental relationships for multi-mechanism elastoplasticity . . . . 83 3.3. Constitutive laws and laboratory tests. . . . . . . . . . . . . . . . . . . . . . . . . . 84 3.4. Characterization of natural cohesive soil behavior. . . . . . . . . . . . . . . . . 86 3.4.1. Analysis of triaxial test results . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 3.4.2. Analysis of oedometer tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 3.4.3. Elasto-viscoplasticity or elastoplasticity?. . . . . . . . . . . . . . . . . . . . 88 3.5. Characterization of frictional soil behavior . . . . . . . . . . . . . . . . . . . . . . 88 3.5.1. Analysis of triaxial test results . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 3.5.2. Elastoplasticity framework for frictional soils. . . . . . . . . . . . . . . . . 91 3.6. Principles for the derivation of elastoplastic models. . . . . . . . . . . . . . . . 92 3.6.1. Elastic behavior. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 3.6.2. Estimation of the plastic behavior . . . . . . . . . . . . . . . . . . . . . . . . . 96 3.6.3. Failure surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 3.6.4. Total and plastic strains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 3.6.5. Plastic potential. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 3.6.6. Yield surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 3.7. Three-dimensional aspect of the models and calculation of geotechnical works. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116 3.8. Examples of perfect elastoplastic models . . . . . . . . . . . . . . . . . . . . . . 117 3.8.1. The Mohr-Coulomb model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 3.8.2. The Drücker-Prager model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 3.9. Examples of elastoplastic models with hardening . . . . . . . . . . . . . . . . 124 3.9.1. University of Cambridge models (Cam-Clay models). . . . . . . . . . 124 3.9.2. Nova model (1982 version). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 3.9.3. Mélanie model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 3.10. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Table of Contents vii 3.11. Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 3.12. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Chapter 4. Elastoplastic Modeling of Soils: Cyclic Loading . . . . . . . . . . . . 143 Bernard CAMBOU and Pierre-Yves HICHER 4.1. Soil behavior under drained loading. . . . . . . . . . . . . . . . . . . . . . . . . . 143 4.1.1. Isotropic and oedometric cyclic loading. . . . . . . . . . . . . . . . . . . . 143 4.1.2. Cyclic triaxial loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 4.1.3. Influence of rotating principal axes . . . . . . . . . . . . . . . . . . . . . . . 148 4.2. Isochoric triaxial tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 4.3. Modeling soil cyclic behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 4.3.1. Difficulties involved in the modeling of the soil cyclic behavior in the framework of elastoplasticity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 4.3.2. The Masing model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 4.4. Models based on one or several independent yield surfaces . . . . . . . . . 160 4.4.1. The CJS model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 4.5. Models based on nested yield surfaces . . . . . . . . . . . . . . . . . . . . . . . . 166 4.5.1. Models with nested yield surfaces: the Mroz model . . . . . . . . . . . 167 4.5.2. Model with infinite yield surfaces: the Hujeux model. . . . . . . . . . 168 Deviatoric mechanisms (k = 1, 2, 3). . . . . . . . . . . . . . . . . . . . . . . . . . . 169 4.5.3. Models with two yield surfaces: the Dafalias model . . . . . . . . . . . 176 4.5.4. Models with two yield surfaces: the Hashigushi model. . . . . . . . . 178 4.5.5. Models with two yield surfaces: CJS 4 model. . . . . . . . . . . . . . . . 179 4.6. Generalized plasticity models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 4.7. Parameter identification for cyclic plasticity models . . . . . . . . . . . . . . 182 4.8. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 4.9. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Chapter 5. Elastoplastic Behavior of Ductile Porous Rocks . . . . . . . . . . . . 187 Jian-Fu SHAO and Shou-Yi XIE 5.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 5.2. Review of typical mechanical behavior of porous rocks. . . . . . . . . . . . 188 5.3. Formulation of the constitutive model. . . . . . . . . . . . . . . . . . . . . . . . . 192 5.3.1. Plastic pore collapse model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 5.3.2. Plastic shearing model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 5.4. Examples of numerical simulations . . . . . . . . . . . . . . . . . . . . . . . . . . 198 5.5. Influence of water saturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 5.6. Creep deformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204 5.7. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206 5.8. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 viii Constitutive Modeling of Soils and Rocks Chapter 6. Incremental Constitutive Relations for Soils. . . . . . . . . . . . . . . 211 René CHAMBON, Félix DARVE and Farid LAOUAFA 6.1. Incremental nature of constitutive relations. . . . . . . . . . . . . . . . . . . . . 211 6.2. Hypoplastic CloE models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 6.2.1. Irreversibility in hypoplasticity. . . . . . . . . . . . . . . . . . . . . . . . . . 214 6.2.2. Limit states. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 6.2.3. A simple example: the 2D Mohr-Coulomb model. . . . . . . . . . . . . 219 6.2.4. Use in boundary value problems. . . . . . . . . . . . . . . . . . . . . . . . . 221 6.2.5. Explicit criterion of localization . . . . . . . . . . . . . . . . . . . . . . . . . 222 6.2.6. Induced anisotropy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 6.2.7. Extension to media with internal length. . . . . . . . . . . . . . . . . . . . 225 6.2.8. Examples of application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 6.3. Incrementally non-linear constitutive relations . . . . . . . . . . . . . . . . . . 229 6.3.1. Formalism. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 6.3.2. Continuous transition between non-linear and octo-linear interpolations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 6.3.3. Significant degenerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 6.3.4. Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 6.3.5. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 6.4. General conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 6.5. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Chapter 7. Viscoplastic Behavior of Soils. . . . . . . . . . . . . . . . . . . . . . . . . . 261 Pierre-Yves HICHER and Isam SHAHROUR 7.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 7.2. Laboratory testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 7.2.1. Strain rate influence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 7.2.2. Creep tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 7.3. Constitutive models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 7.3.1. Modeling framework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 7.3.2. Perzyna’s formulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 7.4. Numerical integration of viscoplastic models . . . . . . . . . . . . . . . . . . . 280 7.5. Viscoplastic models for clays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 7.5.1. Choice of the viscoplastic mechanisms . . . . . . . . . . . . . . . . . . . . 281 7.5.2. Viscoplastic models derived from the elastoplastic Cam-Clay model284 7.5.3. Cyclic viscoplastic modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 7.6. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 7.7. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Chapter 8. Damage Modeling of Rock Materials . . . . . . . . . . . . . . . . . . . . 299 André DRAGON 8.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Table of Contents ix 8.2. Modeling of damage by mesocracks and induced anisotropy . . . . . . . . 302 8.2.1. Preliminaries: damage variables and some micromechanical bases. 302 8.2.2. Anisotropic damage model (basic model - level (i)) . . . . . . . . . . . 306 8.2.3. Comments on the identification of the model’s parameters and on its prediction capability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 8.3. Taking into account mesocrack closure effects: restitution of moduli and complex hysteretic phenomena. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 8.3.1. Normal unilateral effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 8.3.2. Introduction of friction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 8.4. Numerical integration and application examples – concluding notes . . . 336 8.5. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 Chapter 9. Multiscale Modeling of Anisotropic Unilateral Damage in Quasi- brittle Geomaterials: Formulation and Numerical Applications. . . . . . . . . 347 Djimédo KONDO, Qizhi ZHU, Jian-Fu SHAO and Vincent PENSEE 9.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 9.2. Homogenization of microcracked materials: basic principles and macroscopic energy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 9.3. Formulation of the multiscale anisotropic unilateral damage model. . . . 354 9.3.1. Constitutive equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 9.3.2. Friction-damage coupling and evolution laws. . . . . . . . . . . . . . . . 358 9.4. Computational aspects and implementation of the multiscale damage model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 9.4.1. Determination of the tangent matrix . . . . . . . . . . . . . . . . . . . . . . 360 9.4.2. Local integration of the model . . . . . . . . . . . . . . . . . . . . . . . . . . 361 9.5. Illustration of the model predictions for shear tests . . . . . . . . . . . . . . . 363 9.6. Model’s validation for laboratory data including true triaxial tests. . . . . 364 9.6.1. Validation by comparison with conventional triaxial compression tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 9.6.2. Simulations of true triaxial compression tests. . . . . . . . . . . . . . . . 367 9.7. Application on an underground structure: evaluation of the excavation damage zone (EDZ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 9.8. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373 9.9. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 Chapter 10. Poromechanical Behavior of Saturated Cohesive Rocks . . . . . 377 Jian-Fu SHAO and Albert GIRAUD 10.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 10.2. Fundamentals of linear poroelasticity . . . . . . . . . . . . . . . . . . . . . . . . 378 10.3. Fundamentals of poroplasticity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382 10.4. Damage modeling of saturated brittle materials. . . . . . . . . . . . . . . . . 385 10.4.1. Experimental characterization. . . . . . . . . . . . . . . . . . . . . . . . . . 386 x Constitutive Modeling of Soils and Rocks 10.4.2. Numerical modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 10.5. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401 10.6. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402 Chapter 11. Parameter Identification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 Pierre-Yves HICHER and Jian-Fu SHAO 11.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 11.2. Analytical methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 11.3. Correlations applied to parameter identification. . . . . . . . . . . . . . . . . 407 11.4. Optimization methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 11.4.1. Numerical formulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 11.4.2. Examples of parameter identification by means of laboratory testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 11.4.3. Parameter identification from in situ testing. . . . . . . . . . . . . . . . 418 11.5. Conclusion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 11.6. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 List of Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 Preface to the English Edition The French version of this book appeared in 2002 as part of the “Material Mechanics and Engineering” series. The objective of this book was to create as complete as possible a corpus of knowledge and methods in this field. In designing this book on the mechanical behavior of soils and rocks, we gathered together a number of internationally known specialists, who each brought a significant contribution to the knowledge of the experimental behavior of these materials, as well as their constitutive modeling. Our goal was to cover as far as possible the theories at the basis of the different approaches of modeling, and also to address the most recent advances in the field. In translating this book into English, we hope to make available to a wider scientific and engineering public the approaches and school of thought which have dominated the field of geomaterial mechanics in France over the past few decades. We have put together present-day knowledge of mechanical behavior and their theoretical bases in order to construct an original, analytical framework which, we hope, will give readers a useful guide for their own research. Most of the chapters have been updated in order to include the most recent findings on the respective topics. Finally, we wish to dedicate this book to the memory of Professor Jean Biarez, who not only played a ground-breaking role in the history of soil mechanics in France, but remains a source of inspiration to many of us today. Pierre-Yves Hicher Jian-Fu Shao