Schanz Experimental Unsaturated Soil Mechanics

2007
ISBN: 978-3-540-69873-9
Verlag: Springer Berlin Heidelberg
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 112, 505 Seiten

Reihe: Springer Proceedings in Physics

These proceedings are a continuation of the series of International Conferences in Germany entitled 'Mechanics of Unsaturated Soils.' The objective is to discuss and understand unsaturated soil behaviour, so that engineered activities are improved in terms of judgement and quality. In addition to knowledge of classical concepts, it is a challenge to adapt convincing new concepts and present them in such a way that they can be used in engineering practices.

Autoren/Hrsg.

Schanz, T.

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