Schanz Experimental Unsaturated Soil Mechanics

1. Auflage 2007
ISBN: 978-3-540-69873-9
Verlag: Springer-Verlag
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 505 Seiten

Autoren/Hrsg.

Schanz, Tom

Inhaltsverzeichnis

1;Foreword;6
2;Contents;8
3;Part I Microstructure and Fabric;13
3.1;Influence of Relative Density and Clay Fraction on Soils Collapse;14
3.1.1;1 Introduction;14
3.1.2;2 Materials, Equipment and Testing Procedure;15
3.1.3;3 Results and Discussion;17
3.1.4;4 Conclusions;20
3.1.5;References;20
3.2;Microstructure Features in the Behaviour of Engineered Barriers for Nuclear Waste Disposal;21
3.2.1;1 Introduction;21
3.2.2;2 The Microstructure of Compacted Soils;22
3.2.3;3 Effect of Changes in Water Content;30
3.2.4;4 Hydration Mechanisms in Smectites;32
3.2.5;5 Application to Compacted Bentonites;36
3.2.6;6 Concluding Remarks;39
3.2.7;References;40
3.3;Microstructure of Gypsiferous Crust and Its Importance to Unsaturated Soil Behaviour;43
3.3.1;Introduction;43
3.3.2;Materials and Methods;44
3.3.3;Results and Discussion;45
3.3.4;Conclusions;49
3.3.5;References;49
3.4;Fabric Changes in Compacted London Clay Due to Variations in Applied Stress and Suction;51
3.4.1;Introduction;51
3.4.2;Materials and Methods;52
3.4.3;Results;53
3.4.4;Discussion and Conclusions;56
3.4.5;Acknowledgements;57
3.4.6;References;57
3.5;Microstructure of a Lime Stabilised Compacted Silt;59
3.5.1;1 Introduction;59
3.5.2;2 Experimental Procedures;60
3.5.3;3 Results;61
3.5.4;4 Conclusions;65
3.5.5;References;66
4;Part II Measuring Suction;67
4.1;Errors in Total Suction Measurements;68
4.1.1;Introduction;68
4.1.2;Total Suction Measurement Techniques;70
4.1.3;Total Suction Measurement Errors;71
4.1.4;Effects of Total Suction Measurement Errors;76
4.1.5;Conclusions;78
4.1.6;References;78
4.2;Application of a Dew Point Method to Obtain the Soil Water Characteristic;80
4.2.1;Introduction;80
4.2.2;The Dew Point Method;81
4.2.3;Performance Verification;82
4.2.4;Sample Preparation;83
4.2.5;Results;84
4.2.6;Conclusions;86
4.2.7;References;86
4.3;A Comparative Study of Soil Suction Measurement Using Two Different High- Range Psychrometers;87
4.3.1;1 Introduction;87
4.3.2;2 Equipment Used for Total Suction Measurement;88
4.3.3;3 Calibration Protocols;91
4.3.4;4 Water Retention Curves;95
4.3.5;5 Conclusions;99
4.3.6;Acknowledgements;100
4.3.7;References;100
4.4;Determination of the Soil Water Retention Curve with Tensiometers;102
4.4.1;Introduction;102
4.4.2;1 Experimental Set up;103
4.4.3;2 Results;105
4.4.4;Discussion;106
4.4.5;Conclusions;108
4.4.6;References;109
4.5;Tensiometer Development for High Suction Analysis in Laboratory Lysimeters;110
4.5.1;1 Introduction;111
4.5.2;2 Description of the Equipment – Tensiometer;116
4.5.3;3 Results;119
4.5.4;4 Final Comments;120
4.5.5;Acknowledgements;121
4.5.6;References;121
5;Part III Strength and Dilatancy;123
5.1;Dilatancy of Coarse Granular Aggregates;124
5.1.1;Background;124
5.1.2;Suction Controlled Triaxial Tests on Hard Limestone Gravel;129
5.1.3;Dilatancy;132
5.1.4;Summary and Conclusions;138
5.1.5;Acknowledgements;139
5.1.6;References;139
5.2;A Laboratory Investigation into the Effect of Water Content on the CBR of a Subgrade soil;141
5.2.1;Introduction;141
5.2.2;Methodology;142
5.2.3;Discussion of Results;143
5.2.4;Conclusion;147
5.2.5;References;147
5.3;Shear Strength Affected by Suction Tension in Unsaturated Fine Grained Soils?;149
5.3.1;1 Expected Effects of Suction on Strength;149
5.3.2;2 Characterisation of the Tested Materials;151
5.3.3;3 Suction Measurements Results;152
5.3.4;4 Shear Test Results;153
5.3.5;5 Conclusions;156
5.3.6;References;156
5.4;Shear Strength Behaviour of Unsaturated Silty Soil;157
5.4.1;1 Introduction;157
5.4.2;2 Test Procedure and Program;158
5.4.3;3 Results and Discussion;159
5.4.4;4 Conclusion;163
5.4.5;References;163
5.5;Experimental Investigation on the Time Dependent Behaviour of a Multiphase Chalk;164
5.5.1;Introduction;164
5.5.2;Tested Material and Experimental Techniques;165
5.5.3;Void Ratio–Time Relationship;165
5.5.4;Stress-Void Ratio Relationship;167
5.5.5;Creep Evolution;168
5.5.6;Conclusion;169
5.5.7;Acknowledgements;169
5.5.8;References;169
5.6;Testing Unsaturated Soil for Plane Strain Conditions: A New Double Wall Biaxial Device;171
5.6.1;Introduction;171
5.6.2;The New Biaxial Double Wall Cell;172
5.6.3;Calibration;174
5.6.4;Conclusions;178
5.6.5;Acknowledgements;178
5.6.6;References;178
5.7;Influence of State Variables on the Shear Behaviour of an Unsaturated Clay;181
5.7.1;1 Introduction;181
5.7.2;2 Triaxial Tests;182
5.7.3;3 Constitutive Relation;183
5.7.4;4 Conclusions;185
5.7.5;Acknowledgment;185
5.7.6;References;185
5.8;Effect of Capillary and Cemented Bonds on the Strength of Unsaturated Sands;187
5.8.1;1 Introduction;187
5.8.2;2 Experiments: Preparation of the Samples and Protocol of Test;188
5.8.3;3 Results and Discussions;189
5.8.4;4 Numerical Approach;193
5.8.5;5 Conclusion;194
5.8.6;References;194
5.9;Determining the Shear Strength of Unsaturated Silt;196
5.9.1;Introduction;196
5.9.2;Modified Direct Shear Testing Device;198
5.9.3;Procedures;199
5.9.4;Testing Experiment;200
5.9.5;Summary and Conclusions;205
5.9.6;Acknowledgments;206
5.9.7;References;206
5.10;Factors Affecting Tensile Strength Measurement and Modified Tensile Strength Measuring Apparatus for Soil;208
5.10.1;Introduction;208
5.10.2;Test Apparatus;209
5.10.3;Materials and Specimen Preparation;210
5.10.4;Test Conditions;213
5.10.5;Results and Discussions;214
5.10.6;Conclusions;218
5.10.7;Acknowledgements;219
5.10.8;References;219
5.11;The Tensile Strength of Compacted Clays as Affected by Suction and Soil Structure;220
5.11.1;Introduction;220
5.11.2;Soil Structure;221
5.11.3;Test Procedure and Soil Characteristics;222
5.11.4;Test Results;225
5.11.5;Conclusions;226
5.11.6;References;226
6;Part IV Temperature Effects;228
6.1;Modified Isochoric Cell for Temperature Controlled Swelling Pressure Tests;229
6.1.1;Introduction;229
6.1.2;Equipment and Verification;230
6.1.3;Material Used;232
6.1.4;Swelling Pressure Measurement;233
6.1.5;Result and Discussion;235
6.1.6;Conclusion;239
6.1.7;Acknowledgment;240
6.1.8;References;240
6.2;Some Aspects of the Effect of the Temperature on the Behaviour of Unsaturated Sandy Clay;242
6.2.1;1 Introduction;242
6.2.2;2 Materials and Experimental Devices;243
6.2.3;3 Results and discussion;245
6.2.4;4 Conclusion;248
6.2.5;References;249
6.3;Influence of Temperature on the Water Retention Curve of Soils. Modelling and Experiments;250
6.3.1;1 Introduction;250
6.3.2;2 Constitutive Thermo-Hydraulic Model;251
6.3.3;3 Experimenal Validation;253
6.3.4;4 Conclusion;257
6.3.5;References;257
6.4;Thermo-Hydro-Mechanical Behaviour of Compacted Bentonite;258
6.4.1;1 Introduction;258
6.4.2;2 Materials and Methods;259
6.4.3;3 Test Results;261
6.4.4;4 Conclusion;263
6.4.5;References;264
6.5;Retention Curves of Two Bentonites at High Temperature;265
6.5.1;1 Introduction;265
6.5.2;2 Material;266
6.5.3;3 Methodology;266
6.5.4;4 Results;267
6.5.5;5 Summary;270
6.5.6;References;271
7;Part V Volumetric Behaviour – Expansive Materials;273
7.1;Experimental Study on Shrinkage Behaviour and Prediction of Shrinkage Magnitudes of Residual Soils;274
7.1.1;Introduction;274
7.1.2;Materials and Methods;275
7.1.3;Results and Discussion;276
7.1.4;Conclusions;280
7.1.5;References;280
7.2;Assessment of Swelling Deformation of Unsaturated Kaolinite Clay;282
7.2.1;1 Introduction;282
7.2.2;2 Constitutive Relation for Volume Change;283
7.2.3;3 Test Material, Equipment, and Procedure;283
7.2.4;4 Test Results;284
7.2.5;5 Numerical Simulations;285
7.2.6;6 Conclusions;288
7.2.7;Acknowledgements;288
7.2.8;References;288
7.3;Suction and Collapse of Lumpy Spoilheaps in Northwestern Bohemia;289
7.3.1;1 Introduction;289
7.3.2;2 Structure of the Spoilheap Soil;289
7.3.3;3 Field Suction Measurement;291
7.3.4;4 Collapse Potential;292
7.3.5;5 Conclusions;295
7.3.6;References;296
7.4;Oedometer Creep Tests of a Partially Saturated Kaolinite Clay;297
7.4.1;1 Introduction;297
7.4.2;2 Test Material;298
7.4.3;3 Test Equipment and Test Procedure;298
7.4.4;4 Test Results;300
7.4.5;5 Conclusions;302
7.4.6;References;303
7.5;Analysis of the Expansive Clay Hydration under Low Hydraulic Gradient;304
7.5.1;1 Introduction;304
7.5.2;2 Basic THM Formulation;305
7.5.3;3 Infiltration Tests;307
7.5.4;4 Numerical Modelling;308
7.5.5;5 Conclusions;312
7.5.6;References;312
7.6;Moisture Effects on Argillaceous Rocks;314
7.6.1;Introduction;314
7.6.2;Studied Materials;315
7.6.3;Water Retention;315
7.6.4;Swelling Pressure;316
7.6.5;Swelling and Shrinking Strains;317
7.6.6;Self-Sealing;319
7.6.7;Conclusions;320
7.6.8;Acknowledgements;321
7.6.9;References;321
8;Part VI Retention Behaviour;322
8.1;Results from Suction Controlled Laboratory Tests on Unsaturated Bentonite – Verification of a Model;323
8.1.1;1 Background;323
8.1.2;2 Material and Test Methods;324
8.1.3;3 Results;325
8.1.4;4 Analysis;327
8.1.5;5 Conclusions;328
8.1.6;Acknowledgement;329
8.1.7;References;329
8.2;Variation of Degree of Saturation in Unsaturated Silty Soil;330
8.2.1;1 Introduction;330
8.2.2;2 Experimental Study;331
8.2.3;3 Results and Discussion;332
8.2.4;4 Conclusion;335
8.2.5;References;335
8.3;Mechanical Behaviour of Compacted Scaly Clay During Cyclic Controlled- Suction Testing;337
8.3.1;Introduction;337
8.3.2;Experimental Programme;338
8.3.3;Test Results and Interpretation;340
8.3.4;Conclusions;345
8.3.5;References;345
8.4;Prediction of Soil–Water Characteristic Curve Based on Soil Index Properties;347
8.4.1;1 Introduction;347
8.4.2;2 Definitions;349
8.4.3;3 Methods of Obtaining SWCC;350
8.4.4;4 Proposed Model for Predicting the SWCC;352
8.4.5;5 Comparison;353
8.4.6;6 Conclusions;356
8.4.7;Acknowledgements;358
8.4.8;References;358
8.5;Water Balance and Effectiveness of Mineral Landfill Covers – Results of Large Lysimeter Test- Fields;360
8.5.1;Introduction;360
8.5.2;Materials and Methods;361
8.5.3;Data Collection;362
8.5.4;Results and Discussion;363
8.5.5;Conclusions;365
8.5.6;References;367
8.6;A Retention Curve Prediction for Unsaturated Clay Soils;368
8.6.1;1 Introduction;368
8.6.2;2 Test Program, Results and Analysis;372
8.6.3;3 Prediction of the Experimental Results;374
8.6.4;4 Conclusion;376
8.6.5;References;376
8.7;Unsaturated-Zone Leaching and Saturated- Zone Mixing Model in Heterogeneous Layers;378
8.7.1;1 Introduction;378
8.7.2;2 Governing Equation and Boundary and Initial Conditions;379
8.7.3;3 Numerical Implementation;383
8.7.4;4 Program Execution;385
8.7.5;5 Summary;388
8.7.6;References;390
8.8;Prediction of SWCC for Coarse Soils Considering Pore Size Changes;391
8.8.1;Introduction;391
8.8.2;Materials;392
8.8.3;Experimental Methods;394
8.8.4;Results and Discussions;396
8.8.5;Summary and Conclusions;401
8.8.6;Acknowledgements;402
8.8.7;References;402
8.9;The Influence of the Pore Fluid on Desiccation of a Deformable Porous Material;403
8.9.1;Introduction;403
8.9.2;Desiccation Tests;404
8.9.3;Discussion;406
8.9.4;Conclusions and Open Issues;409
8.9.5;Acknowledgment;409
8.9.6;References;409
8.10;Determination of the Soil Water Retention Curve and the Unsaturated Hydraulic Conductivity from the Particle Size Distribution;411
8.10.1;1 Introduction;411
8.10.2;2 Calculation of the Pore Constriction Distribution;412
8.10.3;3 Derivation of Soil Hydraulic Parameters;415
8.10.4;4 Summary and Conclusion;420
8.10.5;References;422
9;Part VII Field Applications;424
9.1;Earthquake-Induced Mudflow Mechanism from a Viewpoint of Unsaturated Soil Dynamics;425
9.1.1;1 Introduction;425
9.1.2;2 Cyclic Triaxial Test for Unsaturated Sandy Soils;427
9.1.3;3 Test Results and Discussion;429
9.1.4;4 Conclusions;432
9.1.5;References;432
9.2;Plate-Load Tests on an Unsaturated Lean Clay;433
9.2.1;Introduction;433
9.2.2;Previous Studies;434
9.2.3;Site Characterization;434
9.2.4;Field Experimental Program;434
9.2.5;Results and Discussion;436
9.2.6;Conclusions;439
9.2.7;References;440
9.3;Selfsealing Barriers of Clay/Mineral Mixtures. The SB Project at the Mont Terri Rock Laboratory;441
9.3.1;1 Introduction;441
9.3.2;2 Laboratory Characterization of Moderately Compacted Clay/ Sand- Mixtures;442
9.3.3;3 In-Situ and Full-Scale Mockup Experiments;444
9.3.4;4 Conclusions;447
9.3.5;Acknowledgements;448
9.3.6;References;448
9.4;Preferential Water Movement in Homogeneous Soils;449
9.4.1;1 Introduction;449
9.4.2;2 Observations on the Full-Scale Dyke Model;450
9.4.3;3 Laboratory Investigations;457
9.4.4;4 Analysis of Experimental Investigations;458
9.4.5;5 Summary and Conclusion;460
9.4.6;References;460
9.5;Compaction Properties of Agricultural Soils;462
9.5.1;Introduction;462
9.5.2;Materials and Methods;463
9.5.3;Experimental Results;464
9.5.4;Discussions;467
9.5.5;Conclusions;468
9.5.6;Acknowledgements;468
9.5.7;References;468
9.6;Bearing Capacity of Model Footings in Unsaturated Soils;470
9.6.1;Introduction;470
9.6.2;Test Equipment;471
9.6.3;Properties of the Tested Soil;471
9.6.4;Typical Experimental Results;472
9.6.5;The Measured and the Predicted SWRC;473
9.6.6;Bearing Capacity of Unsaturated Soils;475
9.6.7;Comparison between the Measured and Predicted Bearing Capacity of Unsaturated Soils;477
9.6.8;Conclusions;478
9.6.9;Acknowledgements;479
9.6.10;References;479
9.7;Influence of Soil Suction on Trench Stability;481
9.7.1;1 Introduction;481
9.7.2;2 Geotechnical Context;482
9.7.3;3 Test Trench Experiment;484
9.7.4;4 Conclusions;486
9.7.5;References;487
10;Index;488