CONSTITUTIVE MODELING OF GEOMATERIALS

Transcription

1 CONSTITUTIVE MODELING OF GEOMATERIALS PRINCIPLES AND APPLICATIONS TERUO NAKAI CRC Press Taylor &Francis Croup Boca Raton London New York CRC Press is an imprint of the Taylor& Francis Croup, an inform* business A SPON PRESS BOOK

2 Preface List of symbols 1 Introduction 1.1 Background Contents of this book 3 PART I Modeling of geomaterials 2 Fundamentals of conventional elastoplasticity 2.1 Introduction One-dimensional modeling of elastoplastic materials Multidimensional modeling of elastoplastic materials 13 3 Modeling of one-dimensional soil behavior 3.1 Introduction Modeling of normally consolidated soils conventional elastoplastic modeling Modeling of overconsolidated soils advanced elastoplastic modeling at stage I Modeling of structured soils (naturally deposited soils) advanced elastoplastic modeling at stage II Modeling ofother features of soils advanced elastoplastic modeling at stage III Loading condition using increment of total change of void ratio and explicit expression in advanced elastoplastic modeling Application of the advanced model (stage III) to time-dependent behavior of soils 40

3 vi Contents 3.8 Meaning of present time-dependent model common and different points to Sekiguchi model Simulation of time-dependent behavior of soil in one-dimensional conditions Application of advanced methods to modeling ofsome other features Temperature-dependent Unsaturated soil behavior 66 behavior 61 4 Ordinary modeling of three-dimensional soil behavior Introduction Outline of ordinary elastoplastic models such as the Cam clay model Discussion on applicability of Cam clay type model in three-dimensional conditions based on test results 94 5 Unified modeling of three-dimensional soil behavior based on the tl} concept Introduction Concept ofmodified stress tij Definition ofty invariants based on the t{j concept Explicit expression of Meaning of the concept 109 and stress and strain increment 5.3 Three-dimensional modeling of normally consolidated soils based on the fi;- concept Formulation of model Explicit expressions ofequations used in the fj;- concept Partial derivatives of yield function and stress variables Derivation ofxcs and Ycs Validation by test data for remolded normally consolidated clay Three-dimensional modeling of various soil features based on the fi; concept Introduction Three-dimensional modeling of overconsolidated soils advanced elastoplastic modeling at stage I 135

4 Contents vii Formulation of model Description of dependency of plastic flow on stress path in constitutive modeling Model validation using test data for remolded normally consolidated and overconsolidated clays Conventional triaxial tests under monotonic and cyclic loadings True triaxial tests under cyclic loadings Plane strain tests on Ko consolidated clay Torsional shear tests on isotropically and anisotropically consolidated clays Model validation using test data for sand Conventional triaxial tests under monotonic and cyclic loadings True triaxial tests under i monotonic loading Three-dimensional modeling of structured soils advanced elastoplastic modeling at stage II Formulation of model Model validation through simulation of structured clays An alternative formulation ofthe model Three-dimensional modeling of other features of soils advanced elastoplastic modeling at stage III General formulation of model Application of model to time-dependent behavior Model validation using simulations of time-dependent behavior of clays Modeling ofsome other features of soil behavior Temperature-dependent behavior Unsaturated soil behavior Conclusions of Part PART 2 Numerical and physical modeling of geotechnical problems Introduction to numerical and physical modeling Introduction to Part 2 211

5 viii Contents 8.2 Modeling the Interface Behavior between Soil and Structure Geomaterials used in 2D and 3D model tests and their material parameters D model ground D model ground Tunneling Two-dimensional trapdoor problems Outline ofmodel tests Outline ofnumerical analyses Results and discussion Series I (single block excavation) Series II (excavations with combination ofthree blocks) Three-dimensional trapdoor problems Outline of model tests Outline of numerical analyses Results and discussion Circular tunneling Outline of model tests Outline of numerical analyses Results and discussion Series I (greenfield ground) Series II (ground with nearby building load) Earth pressure of retaining walls and bearing capacity of foundations Active and passive earth pressure behind retaining walls Outline of model tests Outline of numerical analyses Results and discussion Series I (influence of deflection process ofthe wall) Series II (influence ofdeflection 10.2 Braced open excavation 272 mode of the wall) 270

6 Contents ix Outline of model tests Outline of numerical analyses Results and discussion Strip foundation and piled raft foundation Outline of model tests Outline ofnumerical analyses Results and discussion Reinforced soils Reinforced foundation under uplift loading Outline ofmodel tests Outline ofnumerical analyses Results and discussions Series I (influence of reinforcement direction) Series II (reinforcements stemming from bottom of the foundation) Reinforcing for increasing bearing capacity Outline ofmodel tests Outline ofnumerical analyses Results and discussion Influence of installation depth of reinforcement Influence ofreinforcement length Influence offriction angle of reinforcement Localization and shear band development in element tests Introduction Outline of analyses Results and discussion Conclusions of Part References 329 Index 339