Exadaktylos George E., Vardoulakis Ioannis G. (ed.) Bifurcations, Instabilities, Degradation in Geomechanics

Springer, 2007. — 468 p.The Concept of Bifurcation in Geomechanics
Third Invariant Dependent Single Yield Surface Model and Localization Conditions for High Porosity SandstoneConstitutive Relation
Localization Conditions
Results
Summary and Conclusions
Appendix A
Interpretation of the Scale Effect in Perforation FailureMathematical Model
Model Calibration
Results and Discussion
Conclusions
Experimental Investigation of Instabilities of Granular Materials in Relation to Dilatancy and Fabric IssuesProportional Strain Paths
Biaxial Testing Apparatus
Proportional Strain Path Testing
Stress (Strain) Response Envelopes and Anisotropy
Conclusions
Compactive Cataclastic Flow in Tuffeau de Maastricht Calcarenite: Mechanical Deformation & Permeability ReductionExperimental Procedure and Mechanical Data
Infinitesimal Deformation Theory of Bifurcation of Elastoplastic Solids – Calibration of the Lade and Kim’s Model
Back Test Analysis
Permeability Reduction
Concluding Remarks
Local Second Gradient Models and Damage Mechanics: D Post- Localization Studies in Concrete SpecimensScalar Damage Model
Local Second Gradient Model
D Numerical Simulations
Expansion of the Plastic Region
Conclusions
Entropy and Material Instability in the Quasi-Static Mechanics of Granular Media
Statistics of Kinematics and Stress
Maximum Entropy & Virtual Thermodynamics
Material Instability
Conclusions
A DEM Study of Compaction Band FormationThe Discrete Element Method
Results
Proposed Statistical Approach
Conclusions
Shear Zone Formation in D Random Granular Specimens within Enhanced HypoplasticityHypoplasticity
Micro-Polar Hypoplastic Law
Non-Local Hypoplastic Law
Second-Gradient Hypoplastic Law
FE-Input Data
FE-Results
Conclusions
A Rational Approach to Stress-Dilatancy Modelling Using an Explicit Micromechanical FormulationRowe’s Stress-Dilatancy Formulation Revisited
Effect of Fabric on Stress-Dilatancy Relations
Stress-Dilatancy Formulation with Micromechanical Considerations
Verification
Simplified Procedure and Modified Rowe’s Stress-Dilatancy Relation
Closing Remarks
Micro-Fracture Instabilities in Granular SolidsRVE Problem
Macroscopic Loss of Ellipticity
Numerical Examples and Discussion
Entropy and Material Instability in the Quasi-Static Mechanics of Granular Media
Statistics of Kinematics and Stress
Single Crack Mechanics
Representative Volume Elements Damaged by many Interacting
Microcracks
Effective Stress-Strain Behavior of Microcracked Brittle Materials –
Assessment of Griffith’s Energy Release Rate Criterion
Conclusions
Modeling the Influence of Pressure and Moisture Content on the Disintegration of Weathered Rockfill MaterialsGranular Hardness and Pressure Dependent Limit Void Ratios
Hypoplastic Model
Conclusions
Shear Zone Formation in D Random Granular Specimens within Enhanced HypoplasticityMechanism of Crack Propagation in Non-Uniform Stress Fields
Statistical Properties of Non-Uniform Stress Field Created by Many
Wing Cracks
A Mechanism of Splitting and Oblique Failure in Compression
Conclusions
A Rational Approach to Stress-Dilatancy Modelling Using an Explicit Micromechanical FormulationConstitutive Models for Concrete
Non-Local Approach
FE - Simulations
Conclusions
Kinematics of Shear Zone Deformation in Soft Sensitive ClaysGoverning Equation for Coupled Flow
Pore Water Pressure Generation Dissipation Equation
Finite Element Simulation of Coupled Pore Water and Strain Localization
Results and Discussion
Conclusions
Numerical Analysis of Deformation of Methane Hydrated Contained Soil due to the Dissociation of Gas HydrateSimulation Method
Dissociation of Hydrates
Constitutive Model for Soil
Simulation Examples
Conclusions
Numerical Prediction of Impact Force of Geomaterial Flow against Retaining Structure using CIP MethodNumerical Framework
Laboratory Experiment
Conclusions
Numerical Simulation of the Cracked Brazilian Disc under Diametral CompressionThe Problem
Numerical Analysis and Results
Discussion
Conclusions
Stress Analysis of Multiply Fractured Porous RocksFormulation of the (a) Short-Term and (b) Long-Term Problems
The First Fundamental Boundary Value Problem of the Cracked Body (Prescribed Normal and Tangential Stresses on Cracks
Solution of the Pore Pressure
Numerical Examples