Mechanics of Unsaturated Geomaterials

Professor Lyesse Laloui is Director of the Laboratory of Soil Mechanics, Swiss Federal Institute of Technology, Lausanne, Switzerland and Adjunct Professor in the Civil and Environmental Engineering Department, Duke University, Durham, USA.

Preface xv
Lyesse LALOUI

PART I. FUNDAMENTAL CONCEPTS 1

Chapter 1. Basic Concepts in the Mechanics and Hydraulics of Unsaturated Geomaterials 3
Alessandro TARANTINO

1.1. Water retention mechanisms in capillary systems 4

1.2. Water retention behavior of geomaterials 9

1.3. Water retention mechanisms in geomaterials and the concept of suction 11

1.4. Water flow in capillary systems 18

1.5. Mechanical interactions at the microscale 20

1.6. Microscopic interpretation of volumetric“collapse “ and shear strength 23

1.7. Bibliography 27

Chapter 2. Mechanics of Unsaturated Soils 29
Lyesse LALOUI, Mathieu NUTH and Bertrand FRANCOIS

2.1. Introduction 29

2.2. Stress states 30

2.3. Thermo-hydro-mechanical behavior of unsaturated soils 31

2.4. Effective stress in unsaturated soils 39

2.5. A coupled THM constitutive framework for unsaturated soils 43

2.6. Conclusion 51

2.7. Bibliography 51

Chapter 3. Desiccation Cracking of Soils 55
Herve PERON, Lyesse LALOUI, Liang-Bo HU and Tomasz HUECKEL

3.1. Introduction 55

3.2. Physical processes involved in desiccation cracking of soils 56

3.3. Experimental characterization of desiccation process in soils and its controlling variables 69

3.4. Scenarios of soil desiccation crack pattern formation 74

3.5. Conclusion 79

3.6. Bibliography 80

PART II. EXPERIMENTAL CHARACTERIZATION 87

Chapter 4. Experimental Techniques for Unsaturated Geomaterials 89
Pierre DELAGE

4.1. Introduction 89

4.2. Techniques for controlling suction 90

4.3. Techniques for measuring suction 94

4.4. Mechanical testing devices 97

4.5. Concluding remarks 104

4.6. Bibliography 105

Chapter 5. New Experimental Tools for the Characterization of Highly Overconsolidated Clayey Materials in Unsaturated Conditions 113
Simon SALAGER, Alessio FERRARI and Lyesse LALOUI

5.1. Introduction 113

5.2. Sorption bench 114

5.3. High pressure THM oedometric cell 118

5.4. High pressure and high temperature THM triaxial cell 122

5.5. Conclusions 126

5.6. Bibliography 126

Chapter 6. Field Measurement of Suction, Water Content and Water Permeability 129
Alessandro TARANTINO

6.1. Direct measurement of suction 129

6.2. Indirect measurement of suction 136

6.3. Measurement of water content 140

6.4. Field measurement of water permeability 150

6.5. Bibliography 151

PART III. THEORITICAL DEVELOPMENTS 155

Chapter 7. Hydromechanical Coupling Theory in Unsaturated Geomaterials and Its Numerical Integration 157
Robert CHARLIER, Jean-Pol RADU, Pierre GERARD and Frederic COLLIN

7.1. Introduction – problems to be treated 157

7.2. Numerical tools: the finite element method 163

7.3. Coupling various problems 176

7.4. Acknowledgment 182

7.5. Bibliography 182

Chapter 8. Conservation Laws for Coupled Hydro-Mechanical Processes in Unsaturated Porous Media: Theory and Implementation 185
Ronaldo I. BORJA and Joshua A. WHITE

8.1. Introduction 185

8.2. Mass and momentum conservation laws 187

8.3. Balance of energy and the effective stress 190

8.4. Formulation of boundary-value problem 193

8.5. Numerical example 198

8.6. Summary and conclusions 205

8.7. Acknowledgements 206

8.8. Bibliography 206

Chapter 9. Strain Localization Modeling in Coupled Transient Phenomena 209
Frederic COLLIN, Yannick SIEFFERT and Rene CHAMBON

9.1. Introduction 209

9.2. Experimental evidence 210

9.3. Regularization techniques 212

9.4. Numerical modeling 215

9.5. Applications 221

9.6. Conclusions 227

9.7. Acknowledgment 228

9.8. Bibliography 228

PART IV. ENGINEERING APPLICATIONS 233

Chapter 10. Modeling Landslides in Partially Saturated Slopes Subjected to Rainfall Infiltration 235
John EICHENBERGER, Mathieu NUTH and Lyesse LALOUI

10.1. Introduction: the hazard of shallow landslides 235

10.2. Physical processes in unsaturated soil slopes 236

10.3. Theoretical framework for unsaturated soils 237

10.4. Numerical modeling of an unsaturated soil slope subjected to rainfall events 242

10.5. Conclusion 249

10.6. Bibliography 249

Chapter 11. Thermally Induced Moisture Transport and Pore Pressure Generation in Nearly Saturated Geomaterials 251
Antony P.S. SELVADURAI

11.1. Introduction 251

11.2. Modeling background 252

11.3. Coupled heat and moisture diffusion 253

11.4. Heat-induced moisture transport in a bentonite-sand mixture 257

11.5. Computational simulations of the behavior of bentonite-sand mixture 260

11.6. THM processes in a porous medium 263

11.7. Computational modeling of the THM processes 265

11.8. Experimental modeling of the THM processes in a cementitious block 267

11.9. Comparison of experimental results and computational estimates 270

11.10. Concluding remarks 272

11.11. Acknowledgments 273

11.12. Bibliography 274

Chapter 12. Mechanics of Unsaturated Geomaterials Applied to Nuclear Waste Storage 279
Antonio GENS

12.1. Introduction 279

12.2. THM phenomena in the near field 282

12.3. Theoretical formulation and coupled analysis 284

12.4. Coupled THM analyses of the unsaturated barrier and adjacent rock 286

12.5. Conclusions 299

12.6. Acknowledgments 300

12.7. Bibliography 300

Chapter 13. Soil–Pipeline Interaction in Unsaturated Soils 303
Dilan ROBERT and Kenichi SOGA

13.1. Introduction 303

13.2. Large-scale physical model experiments 304

13.3. Behavior of unsaturated sands 308

13.4. Numerical modeling of the behavior of unsaturated sands 314

13.5. Numerical modeling of the physical model experiments 319

13.6. Dimensionless force – H/D relationship for pipelines in unsaturated soils 321

13.7. Conclusions 323

13.8. Acknowledgments 324

13.9. Bibliography 324

Chapter 14. Coefficient B, Consolidation, and Swelling in Fine Soils Near Saturation in Engineering Practice 327
Luc BOUTONNIER

14.1. Introduction 327

14.2. Model assumptions 328

14.3. How to determine the model? 342

14.4. Why is it interesting for engineers? 345

14.5. Application to Cubzac-les-Ponts experimental embankment 346

14.6. Conclusion 348

14.7. Bibliography 349

Chapter 15. Geomechanical Analysis of River Embankments 353
Cristina JOMMI and Gabriele DELLA VECCHIA

15.1. Introduction 353

15.2. Design specifications and materials 355

15.3. Coupled hydro-mechanical modeling 361

15.4. Simulation and interpretation of experimental data 367

15.5. Final remarks 371

15.6. Bibliography 373

List of Authors 375

Index 379