Kolymbas / Viggiani Mechanics of Natural Solids

1. Auflage 2009
ISBN: 978-3-642-03578-4
Verlag: Springer
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 296 Seiten

This book contains the lectures given at the 2009 Symposium on Mechanics in Natural Solids held in Horto, Greece. It delivers a paradigm for the interconnection of the mechanics of soil, rock, ice and snow and for the interdisciplinary nature of the research.

Autoren/Hrsg.

Kolymbas, Dimitrios

Viggiani, Gioacchino

Inhaltsverzeichnis

1;Title Page;2
2;Preface;5
3;Contents;7
4;Sand as an archetypical natural solid;9
4.1;The magic of sand;9
4.2;Sand as a model of other geomaterials;10
4.2.1;Sand as a model for rock;10
4.2.2;Sand as model of the earth mantle;16
4.2.3;Lava volcanoes - sand volcanoes;16
4.3;The mechanical behaviour of sand;19
4.3.1;The grain skeleton and its physics;19
4.4;Strain localisation and pattern formation;21
4.4.1;Experimental observations—Proportional loading;22
4.4.2;Other experimental evidence;24
4.5;Mathematical models;26
4.5.1;Barodesy;27
4.5.2;Plasticity theory without yield surfaces;32
4.6;References;33
5;The Physics of Granular Mechanics;35
5.1;Introduction;35
5.2;Granular State Variables;37
5.2.1;The Elastic Strain;37
5.2.2;Mass, Entropy and Granular Entropy;39
5.2.3;History Dependence and Fabric Anisotropy;41
5.3;Granular Solid Hydrodynamics (GSH);41
5.3.1;Entropy Production;41
5.3.2;Conservation Laws;43
5.4;Validation of GSH;44
5.4.1;Granular Statics, Tg = T;45
5.4.2;Granular Dynamics, $T_{g} \neq T$;48
5.4.3;Competing Concepts and Misconceptions;51
5.5;References;53
6;Are we there yet? Following the energy trail in cohesionless granular solids;55
6.1;Introduction;55
6.2;Experiments;57
6.2.1;Nonaffine deformation in granular shear;57
6.2.2;Granular friction and stick-slip;62
6.3;Theory;67
6.3.1;Characterization of force chains and their evolution;67
6.3.2;Modeling of force chain evolution;75
6.4;Implications for constitutive theory;81
6.4.1;Thermomicromechanics of a Cosserat Continuum;81
6.4.2;Constitutive model;84
6.4.3;Predictive Capabilities of Model Based on Force Chain Failure;85
6.5;Conclusion;87
6.6;References;88
7;Micromechanical alternatives to phenomenological hardening plasticity;92
7.1;Introduction;92
7.2;Kinematic hardening plasticity and micromechanical roots;94
7.2.1;Phenomenological analog model;94
7.2.2;Alternative analog model;95
7.2.3;The micromechanical interpretation of the second analog;97
7.3;Generalisation of the micromechanical analog;99
7.3.1;A one-dimensional model for random elasto-plastic material;99
7.3.2;The micromechanical interpretation;101
7.3.3;Discussion about the physics of kinematic hardening;102
7.4;Isotropic hardening: phenomenology and micromechanical origins;103
7.4.1;A brief review on breakage mechanics;103
7.4.2;General breakage models;106
7.4.3;Isotropic hardening via breakage model based on linear contact law;108
7.4.4;Isotropic hardening via breakage model based on non-linear contact law;109
7.5;Conclusions;110
7.6;References;110
8;Mechanisms of localized deformation in geomaterials: an experimental insight using full-field measurement techniques;112
8.1;Introduction;112
8.2;Digital Image Correlation;115
8.3;X-ray Computed Tomography;116
8.4;Example 1: localized deformation in a clay rock;119
8.5;Example 2: localized deformation in sand;125
8.6;Conclusions;128
8.7;References;129
9;Two-dimensional Distinct Element Method (DEM) modeling of tectonic fault growth in mechanically layered sequences;133
9.1;Introduction;133
9.2;Geometry of faults in layered sequences;134
9.3;Origin of fault dip refraction;136
9.4;Distinct Element Method;139
9.4.1;Particle Flow Code (PFC);139
9.4.2;Faulting model materials and boundary conditions;141
9.5;Results;142
9.5.1;Fault localization;143
9.5.2;Fault growth;145
9.5.3;Impact of strength and confining pressure on fault zone structure;146
9.5.4;Impact of layering on fault dip;148
9.6;Summary and discussion;150
9.7;References;151
10;When geophysics met geomechanics: Imaging of geomechanical properties and processes using elastic waves;153
10.1;Introduction;153
10.2;Elastic wave propagation in deforming geomaterials;155
10.2.1;Wave equation;155
10.2.2;Sensitivity of elastic wave propagation to geomechanical properties and processes;156
10.3;Laboratory Scale;160
10.3.1;Stress sensitivity;161
10.3.2;Anisotropy, crack density tensors and damage;161
10.3.3;Full-field measurement of elastic properties: ultrasonic tomography;165
10.4;Reservoir Scale;169
10.4.1;Seismic anisotropy detection and mapping;170
10.4.2;Time-lapse seismic and monitoring of fluid-extraction induced reservoir deformation;171
10.5;Conclusions;176
10.6;References;177
11;Fracture of Ice and other Coulombic Materials;182
11.1;Introduction;182
11.2;Structure of Ice;183
11.2.1;Crystal Structure;183
11.2.2;Microstructure;184
11.2.3;Texture-Induced 2D Behavior;185
11.3;Brittle Compressive Failure;185
11.3.1;Failure Envelope and Failure Modes;186
11.3.2;Confinement-Strengthening and Frictional Sliding;188
11.3.3;Micromechanical Processes Underlying Coulombic Faulting;189
11.3.4;The Comb Crack Model of Coulombic Faulting;193
11.3.5;Application to Other Coulombic Materials;193
11.4;Ductile-to Brittle Transition;194
11.4.1;Competition Between Creep and Fracture;196
11.4.2;Micro-Mechanical Model of the Ductile-Brittle Transition;196
11.4.3;Application to Other Coulombic Materials;197
11.5;Coulombic vs. Plastic Faulting;198
11.6;Scale-Independent Fracture Physics: Fracture of the Arctic Sea Ice Cover;199
11.7;Summary;202
11.8;References;203
12;Experimental studies of the viscoplasticty of ice and snow;208
12.1;Introduction;208
12.2;Viscoplasticity of ice;209
12.2.1;Ice is a crystalline material;209
12.2.2;Dislocations in ice;210
12.2.3;Single crystal vs. Polycrystal;211
12.3;Experimental study of the heterogeneous deformation of ice;213
12.3.1;Observations under polarized light;213
12.3.2;Observations under X-ray radiation;217
12.4;Experimental study of the micromechanics of dry snow;221
12.5;Conclusion;224
12.6;References;225
13;Discontinuities in granular materials: Particle-level mechanisms;227
13.1;Introduction;227
13.2;Mineral dissolution and shear strain localization;228
13.2.1;Evolution of internal stresses;228
13.2.2;Shear localization;229
13.2.3;Deformation Field;230
13.3;Desiccation cracks in saturated fine-grained soils;233
13.3.1;Fundamental Mechanism – Fine Grained Soils;233
13.3.2;Initiation – Surface Features;234
13.3.3;Implications;235
13.4;Hydraulic fracture in granular materials;236
13.4.1;Invading and Host Fluids – Particle-Level Forces;236
13.4.2;Fracture Initiation and Propagation;236
13.4.3;Experimental Evidence;237
13.4.4;Discussion on Pore Size Distribution;238
13.5;Conclusions;239
13.6;References;240
14;Grain Crushing, Pore Collapse and Strain Localization in Porous Sandstone;242
14.1;Introduction;242
14.2;Phenomenology of Inelastic Compaction and Failure;243
14.2.1;Strain hardening and shear-enhanced compaction;243
14.2.2;Onset of compactive yield and evolution of the yield cap;245
14.3;Micromechanics of Grain Crushing and Pore Collapse;247
14.4;Onset of Compaction Localization and Propagation of Compaction Band;249
14.4.1;Bifurcation analysis and discrete element modeling of compaction bands;250
14.4.2;Stress conditions for the propagation of compaction bands;253
14.5;Discussion;254
14.6;References;255
15;Long term behaviour and size effects of coarse granular media;258
15.1;Introduction;258
15.2;Particle Breakage;260
15.3;Suction controlled experiments on rockfill;265
15.4;Modelling the behaviour of a rockfill embankment subjected to rainfall;268
15.5;Scale effects;277
15.6;Conclusions;283
15.7;References;283
16;Nature – A Very Clever Experimentalist;285
16.1;Introduction;285
16.2;What Do Experimentalists Provide?;286
16.3;Why Makes Nature So Clever?;291
16.3.1;Material Properties;291
16.3.2;Deformation Systems;294
16.4;Summary Remarks;296
16.5;References;297
17;Author Index;299