Geotechnical Engineering Book
CONTENTS
Preface to the Third Edition i
Preface to the First Edition ii
Purpose and Scope of the Book iv
1 SOIL AND SOIL MECHANICS 1
1.1 Introduction 1
1.2 Development or SoH Mechanics 2
1.3 Fields of Application of Soil mechanics 3
1.4 Soil Formation 4
1.5 Residual and Transported Soils 6
1.6 Some Commonly Used Soil Designations 7
1.7 Structure of Soils 8
1.8 Texture of Soils 9
1.9 Major Soil Deposits of India 9
Summary of Main Points 10
References 10
Questions 11
2 COMPOSITION OF SOIL TERMINOLOGY AND DEFINITIONS 12
2.1 Composition of Soil 12
2.2 Basic Terminology 13
2.3 Certain Important Relationships 17
2.4 Illustrative Examples 21
Summary of Main Points 27
References 27
Questions and Problems 28
3 INDEX PROPERTIES AND CLASSIFICATION TeSTS 30
3.1 Introduction 30
3.2 Soil Colour 30
3.3 Particle Shape 31
3.4 Specific Gravity of Soil Solids 31
3.5 Water Content 34
xIII xlv
3.6
3.7
3.8
3.9
3.10
3.11
·3.12
3.13
Density Index 37
In.-Situ Unit Weight 41
Particle Size Distribution (Mechanical Analysis) 45
Consistency of Clay So4a 68
Activity of Clays 71
Unconfined CompreSHion Strength and Senaitivity of Claya 72
Thixotropy of Clays 73
Illustrative Examples 73
Summary of Main Points sa
References 88
Questions and Problema 89
4 IDENTIFICATION AND CLASSIFICATION OF SOILS 92
4.1 Introduction 92
4.2 Field Identification of Soils 92
4.3 Soil Classification- The Need 94
4.4 Engineering Soil Cla88ification-~l'hle Fe,atures ~.
4.5 Classification Systems-More Co~on Ones 95
4.6 Illustrative Examples 105
Summary of Main Points 109
References 110
Questions and Problems 110
5 SOIL MOISTURe-PERMEABILITY AND CAPILLARITY 112
5.1 Introduction 112
5.2 Soil Moisture and Modes of Occurrence 112
5.3 Neutral and Effective Pressures 11"
5.4 Flow of Water Through Soil-Permeability 116
5.5 Determination of Permeability 121
5.6 Factors Affecting Permeabllity 130
5.7 Values ofPenneability 134
5.B Permeability of Layered Soils 134
*5.9 Capillarity 136
5.10 Illus trative Examples 147
Summary of.Main Points' 160
References 161
Questions and Problems 162
6 SeEPAGE AND FLOW' NETS 165
6.1 Introduction 165
6.2 Flow Net for One-dimensional Flow 165
CONTENTS CONTENTS KY
6.3 Flow Net for Two-Dimensional Flow 168
6.4 Basic Equation for Seepage 172
*6.5 Seepage Through Non-Homogeneous and Anisotropic Soil 176
6.6 Top Flow Line in an Earth Dam 178
*6.7 Radial Flow Nets 187
6.8 Methods of Obtaining Flow Nets 190
6.9 Quicksand 192
6.10 Seepage Forces 193
6.11 Effective Stress in a Soil Mass Under Seepage 194
6.12 lIlustrative Examples 194
Summary of Main Point8 199
References 199
Questions and Problems 200
7 COMPRESSIBILITY AND CONSOLIDATION OF SOILS 202
7.1 Introduction 202
7.2 Compressibility of Soils 202
7.3 A Mechanistic Model for Consolidation 220
7.4 Ten:agW's Theory of One-dimensional Consolidation 224
7.5 Solution ofTerzaghi's Equation for One-dimensional Consolidation 228
7.6 Graphical Presentation of Consolidation Relationships 231
7.7 Evaluation of Coefficient of Consolidation from Odometer Test Data 234
*7.8 Secondary Consolidation 238
7.9 Illustrative Examples 240
Summary of Main Points 248
References 248
Question,; and Problems 249
8 SHEARING STRENGTH OF SOILS 253
8.1 Introduction 253
8.2 Friction 253
8.3 Principal Planes and Principal Stresses-Mohr's Circle 255
8.4 Strength Theories for Soils 260
8.5 Shearing Strength-A Function of Effective Stress 263
*8.6 Hvorslev's True Shear Parameters 264
8.7 Types of Shear Tp.sts Basod on Drainage Conditions 265
B.8 Shearing Strength Tests 266
*8.9 Pore Pressure Parameters 280
*8.10 Stress-Path Approach 282
8.11 Shearing Characteristics of Sand~ 285
8.12 Shearing Characteristics of Clays 290 xvi
9
10
8.13 lIJustrative Examples 297
Summary of Main Points 312
References 313
Questions and Prob1ems 314
STABILITY OF EARTH SLOPES 318
9. 1 Introduction 318
9.2 Infinite Slopes 318
9.3 Finite Slopes 325
9.4 Illustrative Examples 342
Summary of Main Points 349
References 350
Questions and Problems 350
STRESS DISTRIBUTION IN SOIL
10.1 Introduction 352
10.2 Point Load 353
10.3 Line Load 361
10.4 Strip Load 363
352
10.5 Uniform Load on Circular Area 366
10.6 Uniform. Load on Rectangular Area 370
10.7 UniConn Load on Irregular Areas-Newmark's Chart 374
10.8 Approximate Methods 377
10.9 lIluMtrative Examples 378
Summary of Main Points 386
References 387
Questions and Problems 388
11 SETTLEMENT ANALYSIS 390
1.1 Introduction 390
11.2 Data for Settlement Analysia 390
11.3 Settlement 393
· 11.4 Corrections to Computed Settlement 399
· 11.5 Further Factors Affecting Settlement 401
11.6 Other Factors Pertinent to Settlement .c04-
11.7 Settlement Records 407
11.8 Contact Pressure and Active Zone From Pressure Bulb Concept 407
11.9 Dlustrative ExampJes 411
Summary of Main Points 419
Reference8 420
Que8tions and Problems 421 CONTENTS
12 COMPACTION OF SOIL 423
12.1 Introduction 423
12.2 Compaction Phenomenon 423
12.3 Compaction Test 424
12.4 Saturation (Zero-air-voids) Line 425
12.5 Laboratory Compaction Tests 426
12.6 In-situ or Field Compaction 432
*12.7 Compaction of Sand 437
12.8 Compaction versus Consolidation 438
12.9 Illustrative Examples 439
Summary ufMain Points 445
References 446
Questions and Problems 446
xvii
13 LATERAL EARTH PRESSURE AND STABILITY OF RETAINING WALLS 449
13.1 Introduction 449
13.2 Types of Earth-retaining Structures 449
13.3 Lateral Earth Pressures 451
13.4 Earth Pressure at Rest 452
13.5 Earth Pressure Theories 454
13.6 Rankine's Theory 455
13.7 Coulomb's Wedge Theory 470
13.8 Stability Considerations for Retaining Walls 502
13.9 Illustrative Examples 514
Summary of Main Points 536
References 538
Questions and Problems 539
14 BEARING CAPACITY 541
14.1 Introduction and Definitions 541
14.2 Bearing Capacity 542
14.3 Methods of Determining Bearing Capacity 543
14.4 Bearing Capacity from Building Codes 543
14.5 Analytical Methods of Determining Bearing Capacity 546
14.6 Effect of Water Table on Bearing Capacity ,569
14.7 Safe Bearing Capacity 571
14.8 Foundation Settlements 572
14.9 Plate Load Tests 574
·14.10 Bearing Capacity from Penetration Tests 579 ·
·14.11 Bearing Capacity from Model Tests-Housel's Approach 579 xvIII
14.12 Bearing Capacity from Laboratory Tests ~BO
14.13 Bearing Capacity of Sands 580
14.14 Bearing Capacity ofelays 585
14.15 Recommended Practice (1.8) 585
14.16 Illustrative Examples 586
Summary of Main Points 601
References 602
Questions and Problems S03
15 SHALLOW FOUNDATIONS 607
15.1 Introductory Concepts on Foundations 607
15.2 General Types of Foundations S07
15.3 Choice of Foundation Type and Preliminary Selection 613
15.4 Spread Footi ngs 617
15.5 Strap Footings 630
15.6 Combined Footings 631
15.7 Raft Foundations 634
·15.8 Foundations on Non-uniform Soils 639
15.9 Illustrative Examples 641
Summary of Main Points 647
References 648
Questions and Problems S49
16 PILE FOUNDATIONS 651
16.1 In troduction 651
16.2 Classification of Piles 651
16.3 Use of Piles 653
16.4 Pile Driving 654
16.5 Pile Capaci ty 656
16.6 Pile Groups 677
16.7 Settlement of Piles and Pile Groups
· 16.8 Laterally Loaded Piles 685
*16.9 Batter Pites 686
16.10 Design of Pile Foundations 688
683
l S.11 Construction of Pile Foundation.8 689
16.12 J1I ustrative Examples 689
Summary of Main Points 693
References 694
Questions and Problems 695
CONTENTS CONTENTS
17 SOIL STABILISATION 697
17.1 Introduction 697
17.2 Clafl!'lification of the Methods of Stabilisation 697
17.3 Stabilisation of Soil Without Additives 69B
17.4 Stabilisation ofSoi1 with Additives 702
17.5 California BcaTing Ratio 710
"' 17.6 Reinforced Earth and Geosynthetics 716
17.7 Illustrative Examples 71B
Summary of Main Points 721
Refercnces 72 1
Questions and Problems 722
18 SOIL EXPLORATION 724
IB.l Introduction 724
1B.2 Site Investigation 724
18.3 Soil Exploration 726
1B.4 Soil Sampling 732
18.5 Sounding and P.cnetration Tests 738
1B.6 Indirect Methods---Geophysical Methods 746
18.7 The Art of Preparing a Soil Inve~tigation Report 750
IB.8 Illustrative Examples 752
Summary of Main Points 754
References 755
Questions and Problems 756
19 CAISSONS ANO WELL FOUNOATIONS .758
19.1 Introduction 758
19.2 DcsignAspccts of Caissons 759
19.3 Open Caissons 763
19.4 Pneumatic Caissons 764
19.5 Floating Caissons 766
19.6 . Construction Aspects of Caissons 768
19.7 Illustrative Examples on Caissons 770
19.8 Well Foundations 775
19.9 Design Aspects of Well Foundati?ns 778
· 19.10 Lateral StabilityofWeU Foundations 789
19.11 Construction Aspects ofWel1 Foundations 802
19.12 Illustrative Examples on Well Foundations 805
Summary of Main Points 808
References 809
Questions and P roblems 810
xix xx CONTENTS
20 ELEMENTS OF SOIL DYNAMICS ANO MACHINE FOUNDATIONS 812
20.1 Introduction 812
20.2 Fundamentals of Vibration 815
20.3 Fundamentals of Soil Dynamics 828
20.4 Machine Foundations-Special Features 840
20.5 Foundations for Reciprocating Machines 846
20.6 Foundations for Impact Machines 849
20.7 Vibration Isolation 858
20.8 ~onstruction Aspects of Machine Foundations 862
20.9 illustrative Examples 863
Summary of Main Points 873
References 874
Questions and Problems 875
Anl5wers to NumeriCal Problems 877
Objective Questions 880
Answers to Objective Questions 896
Appendix A : A Note on SI Units 901
Appendix B : Notation 905
Author Index 919
Subject Index 921
<sp