SOIL MECHANICS AND FOUNDATIONS THIRD EDITION MUNI BUDHU

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SOIL MECHANICS AND FOUNDATIONS THIRD EDITION MUNI BUDHU

PREFACE

This textbook is written for an undergraduate course in soil mechanics and foundations. It has three primary
objectives. The fi rst is to present basic concepts and fundamental principles of soil mechanics and
foundations in a simple pedagogy using the students’ background in mechanics, physics, and mathematics.
The second is to integrate modern learning principles, teaching techniques, and learning aids to assist
students in understanding the various topics in soil mechanics and foundations. The third is to provide
a solid background knowledge to hopefully launch students in their lifelong learning of geotechnical
engineering issues.
Some of the key features of this textbook are:
• Topics are presented thoroughly and systematically to elucidate the basic concepts and fundamental
principles without diluting technical rigor.
• A large number of example problems are solved to demonstrate or to provide further insights into
the basic concepts and applications of fundamental principles.
• The solution of each example is preceded by a strategy, which is intended to teach students to
think about possible solutions to a problem before they begin to solve it. Each solution provides a
step-by-step procedure to guide the student in problem solving.
• A “What you should be able to do” list at the beginning of each chapter alerts readers to what
they should have learned after studying each chapter, to help students take responsibility for
learning the material.
• Web-based applications including interactive animations, interactive problem solving, interactive
step-by-step examples, virtual soils laboratory, e-quizzes, and much more are integrated with this
textbook.
With the proliferation and accessibility of computers, programmable calculators, and software,
students will likely use these tools in their practice. Consequently, computer program utilities and
generalized equations that the students can program into their calculators are provided rather than
charts.
The content of the book has been signifi cantly enhanced in the third edition:
• Reorganization of chapters—Several chapters in the second edition are now divided into multiple
chapters for ease of use.
• Enhancement of content—The content of each chapter has been enhanced by adding
updated materials and more explanations. In particular, signifi cant improvements have been
made not only to help interpret soil behavior but also to apply the basic concepts to practical
problems.
• Examples and problems—More examples, with more practical “real-world” situations, and more
problems have been added. The examples have been given descriptive titles to make specifi c
examples easier to locate.

ACKNOWLEDGMENTS

I am grateful to the many reviewers who offered many valuable suggestions for improving this textbook.
The following persons were particularly helpful in reviewing the third edition: Juan Lopez, geotechnical
engineer, Golder Associates, Houston, TX; Walid Toufi g, graduate student, University of Arizona, Tucson,
AZ; and Ibrahim Adiyaman, graduate student, University of Arizona, Tucson, AZ.
Ms. Jenny Welter, Mr. Bill Webber, and the staff of John Wiley & Sons were particularly helpful
in getting this book completed. Additional resources are available online at www.wiley.com/college/
budhu.
Also available from the Publisher: Foundations and Earth Retaining Structures, by Muni Budhu
ISBN: 978-0471-47012-0
Website: www.wiley.com/college/budhu
A companion lab manual is available from the Publisher: Soil Mechanics Laboratory Manual, by
Michael Kalinski
The soil mechanics course is often accompanied by a laboratory course, to introduce students to common
geotechnical test methods, test standards, and terminology. Michael Kalinski of the University of
Kentucky has written a lab manual introducing students to the most common soil mechanics tests, and
has included laboratory exercises and data sheets for each test. Brief video demonstrations are also
available online for each of the experiments described in this manual.

CONTENTS

PREFACE iii
NOTES FOR STUDENTS AND INSTRUCTORS v
NOTES FOR INSTRUCTORS vii
CHAPTER 1 INTRODUCTION TO SOIL MECHANICS
AND FOUNDATIONS 1
1.0 Introduction 1
1.1 Marvels of Civil Engineering—The Hidden
Truth 2
1.2 Geotechnical Lessons from Failures 3
CHAPTER 2 GEOLOGICAL CHARACTERISTICS AND
PARTICLE SIZES OF SOILS 5
2.0 Introduction 5
2.1 Defi nitions of Key Terms 5
2.2 Questions to Guide Your Reading 6
2.3 Basic Geology 6
2.3.1 Earth’s Profi le 6
2.3.2 Plate Tectonics 6
2.3.3 Composition of the Earth’s Crust 7
2.3.4 Discontinuities 8
2.3.5 Geologic Cycle and Geological Time 8
2.4 Composition of Soils 10
2.4.1 Soil Formation 10
2.4.2 Soil Types 10
2.4.3 Clay Minerals 11
2.4.4 Surface Forces and Adsorbed
Water 12
2.4.5 Soil Fabric 13
2.5 Determination of Particle Size of Soils—
ASTM D 422 15
2.5.1 Particle Size of Coarse-Grained
Soils 15
2.5.2 Particle Size of Fine-Grained Soils 16
2.5.3 Characterization of Soils Based on
Particle Size 17
2.6 Comparison of Coarse-Grained and Fine-
Grained Soils for Engineering Use 24
2.7 Summary 24
Self-Assessment 25
Exercises 25
CHAPTER 3 SOILS INVESTIGATION 26
3.0 Introduction 26
3.1 Defi nitions of Key Terms 27
3.2 Questions to Guide Your Reading 27
3.3 Purposes of a Soils Investigation 27
3.4 Phases of a Soils Investigation 27
3.5 Soils Exploration Program 29
3.5.1 Soils Exploration Methods 29
3.5.2 Soil Identifi cation in the Field 32
3.5.3 Number and Depths of
Boreholes 34
3.5.4 Soil Sampling 35
3.5.5 Groundwater Conditions 36
3.5.6 Soils Laboratory Tests 37
3.5.7 Types of In Situ or Field Tests 37
3.5.8 Types of Laboratory Tests 43
3.6 Soils Report 46
3.7 Summary 47
Self-Assessment 47
Exercises 47
CHAPTER 4 PHYSICAL SOIL STATES AND SOIL
CLASSIFICATION 48
4.0 Introduction 48
4.1 Defi nitions of Key Terms 49
4.2 Questions to Guide Your Reading 49
4.3 Phase Relationships 50
4.4 Physical States and Index Properties of
Fine-Grained Soils 61
4.5 Determination of the Liquid, Plastic, and
Shrinkage Limits 64
4.5.1 Casagrande Cup Method—
ASTM D 4318 64
4.5.2 Plastic Limit Test—ASTM D 4318 65
4.5.3 Fall Cone Method to Determine
Liquid and Plastic Limits 65
4.5.4 Shrinkage Limit—ASTM D 427 and
D 4943 66
4.6 Soil Classifi cation Schemes 70
4.6.1 Unifi ed Soil Classifi cation System 71
4.6.2 American Society for Testing and
Materials (ASTM) Classifi cation
System 71
4.6.3 AASHTO Soil Classifi cation
System 74
4.6.4 Plasticity Chart 76
4.7 Engineering Use Chart 76
4.8 Summary 80
Self-Assessment 81
Practical Examples 81
Exercises 83
CHAPTER 5 SOIL COMPACTION 87
5.0 Introduction 87
5.1 Defi nitions of Key Terms 88
5.2 Questions to Guide Your Reading 88
5.3 Basic Concept 88
5.4 Proctor Compaction Test—ASTM D 1140 and
ASTM D 1557 89
5.5 Interpretation of Proctor Test Results 91
5.6 Benefi ts of Soil Compaction 95
5.7 Field Compaction 96
5.8 Compaction Quality Control 97
5.8.1 Sand Cone—ASTM D 1556 97
5.8.2 Balloon Test—ASTM D 2167 100
5.8.3 Nuclear Density Meter—ASTM
D 2922, ASTM D 5195 100
5.8.4 Comparison Among the Popular
Compaction Quality Control Tests 101
5.9 Summary 102
Self-Assessment 102
Practical Example 102
Exercises 103
CHAPTER 6 ONE-DIMENSIONAL FLOW OF WATER
THROUGH SOILS 105
6.0 Introduction 105
6.1 Defi nitions of Key Terms 105
6.2 Questions to Guide Your Reading 105
6.3 Head and Pressure Variation in a Fluid at
Rest 106
6.4 Darcy’s Law 109
6.5 Empirical Relationships for k 111
6.6 Flow Parallel to Soil Layers 116
6.7 Flow Normal to Soil Layers 117
6.8 Equivalent Hydraulic Conductivity 117
6.9 Determination of the Hydraulic
Conductivity 118
6.9.1 Constant-Head Test 118
6.9.2 Falling-Head Test 119
6.9.3 Pumping Test to Determine the
Hydraulic Conductivity 122
6.10 Groundwater Lowering by Wellpoints 124
6.11 Summary 126
Self-Assessment 126
Practical Example 126
Exercises 127
CHAPTER 7 STRESSES, STRAINS, AND ELASTIC
DEFORMATIONS OF SOILS 131
7.0 Introduction 131
7.1 Defi nitions of Key Terms 133
7.2 Questions to Guide Your Reading 133
7.3 Stresses and Strains 133
7.3.1 Normal Stresses and Strains 133
7.3.2 Volumetric strain 134
7.3.3 Shear Stresses and Shear Strains 134
7.4 Idealized Stress–Strain Response and
Yielding 135
7.4.1 Material Responses to Normal
Loading and Unloading 135
7.4.2 Material Response to Shear
Forces 137
7.4.3 Yield Surface 138
7.5 Hooke’s Law 139
7.5.1 General State of Stress 139
7.5.2 Principal Stresses 140
7.5.3 Displacements from Strains and Forces
from Stresses 140
7.6 Plane Strain and Axial Symmetric
Conditions 141
7.6.1 Plane Strain Condition 141
7.6.2 Axisymmetric Condition 142
7.7 Anisotropic, Elastic States 145
7.8 Stress and Strain States 146
7.8.1 Mohr’s Circle for Stress States 147
7.8.2 Mohr’s Circle for Strain States 148
7.9 Total and Effective Stresses 150
7.9.1 The Principle of Effective Stress 151
7.9.2 Effective Stresses Due to Geostatic
Stress Fields 152
7.9.3 Effects of Capillarity 153
7.9.4 Effects of Seepage 154
7.10 Lateral Earth Pressure at Rest 161
7.11 Stresses in Soil from Surface Loads 163
7.11.1 Point Load 163
7.11.2 Line Load 165
7.11.3 Line Load Near a Buried Earth-
Retaining Structure 166
7.11.4 Strip Load 166
7.11.5 Uniformly Loaded Circular
Area 168
7.11.6 Uniformly Loaded Rectangular
Area 170
7.11.7 Approximate Method for Rectangular
Loads 172
7.11.8 Vertical Stress Below Arbitrarily
Shaped Area 175
7.11.9 Embankment Loads 177
7.11.10 Infi nite Loads 178
7.12 Summary 178
Self-Assessment 178
Practical Examples 178
Exercises 181
CHAPTER 8 STRESS PATH 186
8.0 Introduction 186
8.1 Defi nitions of Key Terms 187
8.2 Questions to Guide Your Reading 187
8.3 Stress and Strain Invariants 187
8.3.1 Mean Stress 187
8.3.2 Deviatoric or Shear Stress 187
CONTENTS xi
8.3.3 Volumetric Strain 188
8.3.4 Deviatoric or Distortional or Shear
Strain 188
8.3.5 Axisymmetric Condition, s92 5 s93 or
s2 5 s3; ε2 5 ε3 188
8.3.6 Plane Strain, ε2 5 0 188
8.3.7 Hooke’s Law Using Stress and Strain
Invariants 189
8.4 Stress Paths 191
8.4.1 Basic Concept 191
8.4.2 Plotting Stress Paths Using Stress
Invariants 192
8.4.3 Plotting Stress Paths Using Two-
Dimensional Stress Parameters 196
8.4.4 Procedure for Plotting Stress
Paths 197
8.5 Summary 203
Self-Assessment 203
Practical Example 203
Exercises 205
CHAPTER 9 ONE-DIMENSIONAL CONSOLIDATION
SETTLEMENT OF FINE-GRAINED SOILS 207
9.0 Introduction 207
9.1 Defi nitions of Key Terms 208
9.2 Questions to Guide Your Reading 209
9.3 Basic Concepts 209
9.3.1 Instantaneous Load 210
9.3.2 Consolidation Under a Constant
Load—Primary Consolidation 211
9.3.3 Secondary Compression 211
9.3.4 Drainage Path 212
9.3.5 Rate of Consolidation 212
9.3.6 Effective Stress Changes 212
9.3.7 Void Ratio and Settlement Changes
Under a Constant Load 213
9.3.8 Effects of Vertical Stresses on Primary
Consolidation 213
9.3.9 Primary Consolidation
Parameters 216
9.3.10 Effects of Loading History 215
9.3.11 Overconsolidation Ratio 216
9.3.12 Possible and Impossible Consolidation
Soil States 216
9.4 Calculation of Primary Consolidation
Settlement 216
9.4.1 Effects of Unloading/Reloading
of a Soil Sample Taken from the
Field 216
9.4.2 Primary Consolidation Settlement of
Normally Consolidated Fine-Grained
Soils 217
9.4.3 Primary Consolidation Settlement
of Overconsolidated Fine-Grained
Soils 218
xii CONTENTS
9.4.4 Procedure to Calculate Primary
Consolidation Settlement 218
9.4.5 Thick Soil Layers 219
9.5 One-Dimensional Consolidation
Theory 225
9.5.1 Derivation of Governing
Equation 225
9.5.2 Solution of Governing Consolidation
Equation Using Fourier Series 227
9.5.3 Finite Difference Solution of
the Governing Consolidation
Equation 229
9.6 Secondary Compression Settlement 234
9.7 One-Dimensional Consolidation Laboratory
Test 235
9.7.1 Oedometer Test 235
9.7.2 Determination of the Coeffi cient of
Consolidation 236
9.7.2.1 Root Time Method (Square
Root Time Method) 236
9.7.2.2 Log Time Method 237
9.7.3 Determination of Void Ratio at the
End of a Loading Step 238
9.7.4 Determination of the Past Maximum
Vertical Effective Stress 239
9.7.5 Determination of Compression
and Recompression Indices 240
9.7.6 Determination of the Modulus of
Volume Change 240
9.7.7 Determination of the Secondary
Compression Index 241
9.8 Relationship Between Laboratory and Field
Consolidation 243
9.9 Typical Values of Consolidation
Settlement Parameters and Empirical
Relationships 245
9.10 Preconsolidation of Soils Using Wick
Drains 246
9.11 Summary 249
Self-Assessment 250
Practical Examples 250
Exercises 257
CHAPTER 10 SHEAR STRENGTH OF SOILS 261
10.0 Introduction 261
10.1 Defi nitions of Key Terms 262
10.2 Questions to Guide Your Reading 262
10.3 Typical Response of Soils to Shearing
Forces 262
10.3.1 Effects of Increasing the Normal
Effective Stress 265
10.3.2 Effects of Overconsolidation Ratio 266
10.3.3 Effects of Drainage of Excess
Porewater Pressure 267
10.3.4 Effects of Cohesion 267
10.3.5 Effects of Soil Tension 268
10.3.6 Effects of Cementation 269
10.4 Four Models for Interpreting the Shear
Strength of Soils 269
10.4.1 Coulomb’s Failure Criterion 270
10.4.2 Taylor’s Failure Criterion 274
10.4.3 Mohr–Coulomb Failure Criterion 275
10.4.4 Tresca Failure Criterion 277
10.5 Practical Implications of Failure Criteria 278
10.6 Interpretation of the Shear Strength of
Soils 280
10.7 Laboratory Tests to Determine Shear Strength
Parameters 286
10.7.1 A Simple Test to Determine Friction
Angle of Clean, Coarse-Grained
Soils 286
10.7.2 Shear Box or Direct Shear Test 286
10.7.3 Conventional Triaxial
Apparatus 291
10.7.4 Unconfi ned Compression (UC)
Test 293
10.7.5 Consolidated Drained (CD)
Compression Test 295
10.7.6 Consolidated Undrained (CU)
Compression Test 300
10.7.7 Unconsolidated Undrained (UU)
Test 304
10.8 Porewater Pressure Under Axisymmetric
Undrained Loading 305
10.9 Other Laboratory Devices to Measure Shear
Strength 307
10.9.1 Simple Shear Apparatuses 307
10.9.2 True Triaxial Apparatus 311
10.9.3 Hollow-Cylinder Apparatus 312
10.10 Field Tests 313
10.10.1 Vane Shear Test (VST) 313
10.10.2 The Standard Penetration Test
(SPT) 313
10.10.3 Cone Penetrometer Test (CPT) 314
10.11 Specifying Laboratory Strength Tests 314
10.12 Empirical Relationships for Shear Strength
Parameters 314
10.13 Summary 316
Self-Assessment 316
Practical Examples 316
Exercises 320
CHAPTER 11 A CRITICAL STATE MODEL TO
INTERPRET SOIL BEHAVIOR 324
11.0 Introduction 324
11.1 Defi nitions of Key Terms 325
11.2 Questions to Guide Your Reading 325
11.3 Basic Concepts 326
11.3.1 Parameter Mapping 326
11.3.2 Failure Surface 328
CONTENTS xiii
11.3.3 Soil Yielding 328
11.3.4 Prediction of the Behavior of
Normally Consolidated and Lightly
Overconsolidated Soils Under
Drained Condition 329
11.3.5 Prediction of the Behavior of
Normally Consolidated and Lightly
Overconsolidated Soils Under
Undrained Condition 332
11.3.6 Prediction of the Behavior of Heavily
Overconsolidated Soils Under Drained
and Undrained Condition 335
11.3.7 Prediction of the Behavior of Coarse-
Grained Soils Using CSM 337
11.3.8 Critical State Boundary 337
11.3.9 Volume Changes and Excess
Porewater Pressures 338
11.3.10 Effects of Effective and Total Stress
Paths 338
11.4 Elements of the Critical State Model 339
11.4.1 Yield Surface 339
11.4.2 Critical State Parameters 340
11.4.2.1 Failure Line in (p9, q)
Space 340
11.4.2.2 Failure Line in (p9, e)
Space 342
11.5 Failure Stresses from the Critical State
Model 345
11.5.1 Drained Triaxial Test 345
11.5.2 Undrained Triaxial Test 347
11.6 Modifi cations of CSM and Their Practical
Implications 361
11.7 Relationships from CSM that Are of Practical
Signifi cance 365
11.7.1 Relationship Between Normalized
Yield (peak) Shear Stress and Critical
State Shear Stress Under Triaxial
Drained Condition 365
11.7.2 Relationship Among the Tension
Cutoff, Mean Effective Stress, and
Preconsolidation Stress 367
11.7.3 Relationship Among Undrained
Shear Strength, Critical State
Friction Angle, and Preconsolidation
Ratio 369
11.7.4 Relationship Between the Normalized
Undrained Shear Strength at
the Critical State for Normally
Consolidated and Overconsolidated
Fine-Grained Soils 370
11.7.5 Relationship Between the Normalized
Undrained Shear Strength of One-
Dimensionally Consolidated or
Ko-Consolidated and Isotropically
Consolidated Fine-Grained
Soils 371
11.7.6 Relationship Between the Normalized
Undrained Shear Strength at Initial
Yield and at Critical State for
Overconsolidated Fine-Grained Soils
Under Triaxial Test Condition 374
11.7.7 Undrained Shear Strength Under
Direct Simple Shear (plane strain)
Condition 376
11.7.8 Relationship Between Direct Simple
Shear Tests and Triaxial Tests 377
11.7.9 Relationship for the Application of
Drained and Undrained Conditions in
the Analysis of Geosystems 378
11.7.10 Relationship Among Excess Porewater
Pressure, Preconsolidation Ratio, and
Critical State Friction Angle 381
11.7.11 Undrained Shear Strength of Clays at
the Liquid and Plastic Limits 382
11.7.12 Vertical Effective Stresses at the
Liquid and Plastic Limits 382
11.7.13 Compressibility Indices (l and Cc) and
Plasticity Index 382
11.7.14 Undrained Shear Strength, Liquidity
Index, and Sensitivity 383
11.7.15 Summary of Relationships Among
Some Soil Parameters from CSM 383
11.8 Soil Stiffness 389
11.9 Strains from the Critical State Model 393
11.9.1 Volumetric Strains 393
11.9.2 Shear Strains 395
11.10 Calculated Stress–Strain Response 399
11.10.1 Drained Compression Tests 400
11.10.2 Undrained Compression Tests 400
11.11 Application of CSM to Cemented Soils 407
11.12 Summary 408
Self-Assessment 409
Practical Examples 409
Exercises 418
CHAPTER 12 BEARING CAPACITY OF SOILS AND
SETTLEMENT OF SHALLOW FOUNDATIONS 422
12.0 Introduction 422
12.1 Defi nitions of Key Terms 423
12.2 Questions to Guide Your Reading 424
12.3 Allowable Stress and Load and Resistance
Factor Design 425
12.4 Basic Concepts 426
12.4.1 Soil Response to a Loaded
Footing 426
12.4.2 Conventional Failure Surface Under a
Footing 428
12.5 Collapse Load Using the Limit Equilibrium
Method 429
12.6 Bearing Capacity Equations 431
12.7 Mat Foundations 443
12.8 Bearing Capacity of Layered Soils 445
12.9 Building Codes Bearing Capacity Values 447
12.10 Settlement 448
12.11 Settlement Calculations 450
12.11.1 Immediate Settlement 450
12.11.2 Primary Consolidation
Settlement 454
12.12 Determination of Bearing Capacity and
Settlement of Coarse-Grained Soils from
Field Tests 457
12.12.1 Standard Penetration Test (SPT) 457
12.12.2 Cone Penetration Test (CPT) 460
12.12.3 Plate Load Test (PLT) 463
12.13 Shallow Foundation Analysis Using CSM 464
11.13.1 Heavily Overconsolidated
Fine-Grained Soil 465
12.13.2 Dense, Coarse-Grained Soils 471
12.14 Horizontal Elastic Displacement and
Rotation 485
12.15 Summary 486
Self-Assessment 487
Practical Examples 487
Exercises 506
CHAPTER 13 PILE FOUNDATIONS 509
13.0 Introduction 509
13.1 Defi nitions of Key Terms 509
13.2 Questions to Guide Your Reading 510
13.3 Types of Piles and Installations 511
13.3.1 Concrete Piles 512
13.3.2 Steel Piles 512
13.3.3 Timber Piles 512
13.3.4 Plastic Piles 512
13.3.5 Composites 512
13.3.6 Pile Installation 514
13.4 Basic Concept 515
13.5 Load Capacity of Single Piles 521
13.6 Pile Load Test (ASTM D 1143) 522
13.7 Methods Using Statics for Driven Piles 531
13.7.1 a-Method 531
13.7.1.1 Skin Friction 531
13.7.1.2 End Bearing 531
13.7.2 b-Method 532
13.7.2.1 Skin Friction 532
13.7.2.2 End Bearing 534
13.8 Pile Load Capacity of Driven Piles Based on
SPT and CPT Results 539
13.8.1 SPT 540
13.8.2 CPT 540
13.9 Load Capacity of Drilled Shafts 544
13.10 Pile Groups 546
13.11 Elastic Settlement of Piles 552
13.12 Consolidation Settlement Under a Pile
Group 554
xiv CONTENTS
13.13 Procedure to Estimate Settlement of Single
and Group Piles 555
13.14 Settlement of Drilled Shafts 559
13.15 Piles Subjected to Negative Skin
Friction 560
13.16 Pile-Driving Formulas and Wave
Equation 562
13.17 Laterally Loaded Piles 563
13.18 Micropiles 567
13.19 Summary 568
Self-Assessment 568
Practical Examples 568
Exercises 575
CHAPTER 14 TWO-DIMENSIONAL FLOW OF WATER
THROUGH SOILS 579
14.0 Introduction 579
14.1 Defi nitions of Key Terms 579
14.2 Questions to Guide Your Reading 580
14.3 Two-Dimensional Flow of Water Through
Porous Media 580
14.4 Flownet Sketching 583
14.4.1 Criteria for Sketching Flownets 583
14.4.2 Flownet for Isotropic Soils 583
14.4.3 Flownet for Anisotropic Soil 585
14.5 Interpretation of Flownet 586
14.5.1 Flow Rate 586
14.5.2 Hydraulic Gradient 586
14.5.3 Static Liquefaction, Heaving, Boiling,
and Piping 586
14.5.4 Critical Hydraulic Gradient 587
14.5.5 Porewater Pressure Distribution 587
14.5.6 Uplift Forces 587
14.6 Finite Difference Solution for Two-
Dimensional Flow 592
14.7 Flow Through Earth Dams 598
14.8 Soil Filtration 602
14.9 Summary 603
Self-Assessment 603
Practical Examples 603
Exercises 606
CHAPTER 15 STABILITY OF EARTH-RETAINING
STRUCTURES 610
15.0 Introduction 610
15.1 Defi nitions of Key Terms 611
15.2 Questions to Guide Your Reading 611
15.3 Basic Concepts of Lateral Earth
Pressures 612
15.4 Coulomb’s Earth Pressure Theory 620
15.5 Rankine’s Lateral Earth Pressure for a Sloping
Backfi ll and a Sloping Wall Face 623
15.6 Lateral Earth Pressures for a Total Stress
Analysis 625
15.7 Application of Lateral Earth Pressures to
Retaining Walls 627
15.8 Types of Retaining Walls and Modes of
Failure 630
15.9 Stability of Rigid Retaining Walls 633
15.9.1 Translation 633
15.9.2 Rotation 634
15.9.3 Bearing Capacity 634
15.9.4 Deep-Seated Failure 634
15.9.5 Seepage 635
15.9.6 Procedures to Analyze Rigid
Retaining Walls 635
15.10 Stability of Flexible Retaining Walls 643
15.10.1 Analysis of Sheet Pile Walls in
Uniform Soils 643
15.10.2 Analysis of Sheet Pile Walls in Mixed
Soils 645
15.10.3 Consideration of Tension Cracks in
Fine-Grained Soils 645
15.10.4 Methods of Analyses 646
15.10.5 Analysis of Cantilever Sheet Pile
Walls 648
15.10.6 Analysis of Anchored Sheet Pile
Walls 648
15.11 Braced Excavation 659
15.12 Mechanical Stabilized Earth Walls 666
15.12.1 Basic Concepts 667
15.12.2 Stability of Mechanical Stabilized
Earth Walls 667
15.13 Other Types of Retaining Walls 675
15.13.1 Modular Gravity Walls 675
15.13.2 In Situ Reinforced Walls 676
15.13.3 Chemically Stabilized Earth Walls
(CSE) 676
15.14 Summary 676
Self-Assessment 676
Practical Examples 676
Exercises 682
CHAPTER 16 SLOPE STABILITY 687
16.0 Introduction 687
16.1 Defi nitions of Key Terms 687
16.2 Questions to Guide Your Reading 688
16.3 Some Types of Slope Failure 688
16.4 Some Causes of Slope Failure 689
16.4.1 Erosion 689
16.4.2 Rainfall 691
16.4.3 Earthquakes 691
16.4.4 Geological Features 691
16.4.5 External Loading 691
16.4.6 Construction Activities 691
16.4.6.1 Excavated Slopes 691
16.4.6.2 Fill Slopes 692
16.4.7 Rapid Drawdown 692
CONTENTS xv
16.5 Infi nite Slopes 692
16.6 Two-Dimensional Slope Stability Analyses 697
16.7 Rotational Slope Failures 697
16.8 Method of Slices 699
16.8.1 Bishop’s Method 699
16.8.2 Janbu’s Method 702
16.8.3 Cemented Soils 703
16.9 Application of the Method of Slices 704
16.10 Procedure for the Method of Slices 705
16.11 Stability of Slopes with Simple Geometry 713
16.11.1 Taylor’s Method 713
16.11.2 Bishop–Morgenstern Method 714
16.12 Factor of Safety (FS) 715
16.13 Summary 716
Self-Assessment 716
Practical Example 716
Exercises 719
APPENDIX A A COLLECTION OF FREQUENTLY USED
SOIL PARAMETERS AND CORRELATIONS 723
APPENDIX B DISTRIBUTION OF VERTICAL STRESS
AND ELASTIC DISPLACEMENT UNDER A UNIFORM
CIRCULAR LOAD 730
APPENDIX C DISTRIBUTION OF SURFACE STRESSES
WITHIN FINITE SOIL LAYERS 731
APPENDIX D LATERAL EARTH PRESSURE
COEFFICIENTS (KERISEL AND ABSI, 1990) 734
REFERENCES 738
INDEX 742
xvi CONTENTS