## Contents

Preface to the First Edition………………………………………………………………………….xvii

Preface to the Second Edition……………………………………………………………………….xix

The Authors……………………………………………………………………………………………. xxiii

Chapter 1 Introduction……………………………………………………………………………..1

1.1 Soil Mechanics and Related Fields………………………………………1

1.2 Biography of Dr. Karl von Terzaghi…………………………………….1

1.3 Uniqueness of Soils…………………………………………………………..4

1.4 Approaches to Soil Mechanics Problems……………………………..4

1.5 Examples of Soil Mechanics Problems………………………………..5

1.5.1 Leaning Tower of Pisa……………………………………………5

1.5.2 Sinking of Kansai International Airport…………………..5

1.5.3 Liquefaction—Sand Becomes Liquid during

Earthquake…………………………………………………………..7

References…………………………………………………………………………………8

Chapter 2 Physical Properties of Soils……………………………………………………….9

2.1 Introduction……………………………………………………………………..9

2.2 Origin of Soils………………………………………………………………….9

2.3 Soil Particle Shapes………………………………………………………… 10

2.4 Definitions of Terms with Three-Phase Diagram……………….. 12

2.5 Particle Size and Gradation……………………………………………… 18

2.6 Summary……………………………………………………………………….24

References……………………………………………………………………………….24

Problems………………………………………………………………………………….24

Chapter 3 Clays and Their Behavior………………………………………………………..29

3.1 Introduction……………………………………………………………………29

3.2 Clay Minerals…………………………………………………………………29

3.2.1 Kaolinite Clay…………………………………………………….30

3.2.2 Montmorillonite Clay…………………………………………..30

3.2.3 Illite Clay…………………………………………………………… 33

3.3 Clay Shapes and Surface Areas…………………………………………34

3.4 Surface Charge of Clay Particles………………………………………. 35

3.5 Clay–Water Systems……………………………………………………….. 35

3.6 Interaction of Clay Particles……………………………………………..37

3.6.1 Van der Waal’s Force (Attractive)………………………….38

3.6.2 Dipole–Cation–Dipole Attraction………………………….38

3.6.3 Cation Linkage (Attractive)…………………………………..38

3.6.4 Cation–Cation Repulsive Force…………………………….38

3.6.5 Anion–Anion Repulsive Force………………………………38

3.7 Clay Structures……………………………………………………………….40

3.8 Atterberg Limits and Indices……………………………………………. 41

3.9 Activity…………………………………………………………………………. 45

3.10 Swelling and Shrinkage of Clays………………………………………46

3.11 Sensitivity and Quick Clay………………………………………………. 47

3.12 Clay Versus Sand…………………………………………………………….49

3.13 Summary……………………………………………………………………….50

References……………………………………………………………………………….50

Problems…………………………………………………………………………………. 51

Chapter 4 Soil Classification…………………………………………………………………… 53

4.1 Introduction…………………………………………………………………… 53

4.2 Unified Soil Classification System (USCS)………………………… 53

4.2.1 For G or S………………………………………………………….. 55

4.2.2 For C, M, O, or Pt………………………………………………..56

4.3 AASHTO Classification System………………………………………. 57

4.4 Summary………………………………………………………………………. 61

References………………………………………………………………………………. 62

Problems…………………………………………………………………………………. 62

Chapter 5 Compaction…………………………………………………………………………….65

5.1 Introduction……………………………………………………………………65

5.2 Relative Density………………………………………………………………65

5.3 Laboratory Compaction Test……………………………………………. 67

5.3.1 Standard Proctor Test Procedure…………………………… 67

5.3.2 Compaction Curve………………………………………………68

5.3.3 Zero Air Void Curve…………………………………………… 70

5.3.4 Compaction Energy…………………………………………….. 71

5.4 Specification of Compaction in the Field…………………………… 72

5.5 Field Compaction Methods……………………………………………… 74

5.5.1 Compaction Equipment……………………………………….. 74

5.5.2 Dynamic Compaction…………………………………………. 76

5.6 Field Density Determinations……………………………………………77

5.6.1 Sand Cone Method………………………………………………77

5.6.2 Other Field Density Methods………………………………..80

5.7 California Bearing Ratio Test…………………………………………..80

5.8 Summary………………………………………………………………………. 81

References……………………………………………………………………………….82

Problems………………………………………………………………………………….82

Chapter 6 Flow of Water through Soils…………………………………………………….85

6.1 Introduction……………………………………………………………………85

6.2 Hydraulic Heads and Water Flow………………………………………85

6.3 Darcy’s Equation…………………………………………………………….87

6.4 Coefficient of Permeability……………………………………………….89

6.4.1 Hazen’s Formula………………………………………………….89

6.4.2 Chapuis’s Formula……………………………………………….90

6.4.3 Kozeny and Carman’s Formula……………………………..90

6.5 Laboratory Determination of Coefficient of Permeability……. 91

6.5.1 Constant Head Permeability Test………………………….. 91

6.5.2 Falling Head Permeability Test……………………………..92

6.6 Field Determination of Coefficient of Permeability……………..93

6.6.1 Unconfined Permeable Layer Underlain by

Impervious Layer………………………………………………..94

6.6.2 Confined Aquifer…………………………………………………94

6.7 Flow Net………………………………………………………………………..95

6.7.1 One-Dimensional Flow Net………………………………….95

6.7.2 Flow Net for Two-Dimensional Problems with

Isotropic Soils……………………………………………………..97

6.7.3 Pressure Heads in Flow Net………………………………….99

6.8 Boundary Water Pressures…………………………………………….. 100

6.9 Summary…………………………………………………………………….. 106

References…………………………………………………………………………….. 106

Problems……………………………………………………………………………….. 106

Chapter 7 Effective Stress……………………………………………………………………… 111

7.1 Introduction…………………………………………………………………. 111

7.2 Total Stress versus Effective Stress…………………………………. 111

7.3 Effective Stress Computations in Soil Mass…………………….. 111

7.3.1 Dry Soil Layers………………………………………………… 112

7.3.2 Soil Layers with Steady Water Table…………………… 113

7.3.3 Totally Submerged Soil Layers…………………………… 115

7.4 Effective Stress Change Due to Water Table Change………… 116

7.5 Capillary Rise and Effective Stress…………………………………. 117

7.6 Effective Stress with Water Flow……………………………………. 120

7.7 Quicksand (Sand Boiling)……………………………………………… 122

7.8 Heave of Clay Due to Excavation…………………………………….124

7.8.1 Dry Excavation………………………………………………….124

7.8.2 Wet Excavation…………………………………………………. 125

7.9 Summary…………………………………………………………………….. 127

References…………………………………………………………………………….. 127

Problems……………………………………………………………………………….. 127

Chapter 8 Stress Increments in Soil Mass……………………………………………… 135

8.1 Introduction…………………………………………………………………. 135

8.2 2:1 Approximate Slope Method………………………………………. 135

8.3 Vertical Stress Increment Due to a Point Load…………………. 137

8.4 Vertical Stress Increment Due to a Line Load………………….. 140

8.5 Vertical Stress Increment Due to a Strip Load………………….. 141

8.6 Vertical Stress Increment under a Circular Footing…………… 145

8.7 Vertical Stress Increment under an Embankment Load……… 146

8.8 Vertical Stress Increment under Corner of Rectangular

Footing………………………………………………………………………… 150

8.9 Vertical Stress Increment under Irregularly Shaped

Footing…………………………………………………………………….154

8.10 Summary…………………………………………………………………….. 157

References…………………………………………………………………………….. 157

Problems……………………………………………………………………………….. 157

Chapter 9 Settlements…………………………………………………………………………… 163

9.1 Introduction…………………………………………………………………. 163

9.2 Elastic Settlements………………………………………………………… 163

9.3 Primary Consolidation Settlement………………………………….. 166

9.4 One-Dimensional Primary Consolidation Model……………… 166

9.5 Terzaghi’s Consolidation Theory……………………………………. 167

9.6 Laboratory Consolidation Test……………………………………….. 176

9.7 Determination of Cv……………………………………………………… 177

9.7.1 Log t Method……………………………………………………. 177

9.7.2 t Method……………………………………………………….. 178

9.8 e-log σ Curve……………………………………………………………….. 179

9.9 Normally Consolidated and Overconsolidated Soils…………. 182

9.10 Final Consolidation Settlement for Thin Clay Layer…………. 185

9.10.1 Normally Consolidated Soils……………………………… 185

9.10.2 Overconsolidated Soils………………………………………. 187

9.11 Consolidation Settlement for Multilayers or a Thick

Clay Layer…………………………………………………………………… 188

9.12 Summary of Primary Consolidation Computations…………… 191

9.12.1 The “How Much” Problem…………………………………. 191

9.12.2 The “How Soon” Problem (Rate Problem)…………… 192

9.13 Secondary Compression………………………………………………… 192

9.14 Allowable Settlement…………………………………………………….. 194

9.15 Ground-Improving Techniques against Consolidation

Settlement……………………………………………………………………. 195

9.15.1 Vertical Drain (Paper Drain, Wick Drain,

and Sand Drain) Techniques………………………………. 196

9.15.2 Preloading Technique………………………………………… 197

9.15.3 Vacuum Consolidation Technique……………………….. 197

9.16 Summary…………………………………………………………………….. 198

References…………………………………………………………………………….. 198

Problems……………………………………………………………………………….. 199

Chapter 10 Mohr’s Circle in Soil Mechanics…………………………………………….207

10.1 Introduction………………………………………………………………….207

10.2 Concept of Mohr’s Circle……………………………………………….207

10.3 Stress Transformation…………………………………………………….207

10.4 Mohr’s Circle Construction……………………………………………. 211

10.5 Sign Convention of Shear Stress…………………………………….. 213

10.6 Pole (Origin of Planes) of Mohr’s Circle………………………….. 214

10.7 Summary of Usage of Mohr’s Circle and Pole………………….. 218

10.8 Examples of Usage of Mohr’s Circle and Pole in

Soil Mechanics…………………………………………………………….. 218

10.8.1 Shear Failure Direction on Soil Specimen……………. 218

10.8.2 Failure Zone in Rankine’s Lateral Earth

Pressure Theory……………………………………………….. 219

10.9 Summary……………………………………………………………………..220

Reference……………………………………………………………………………….220

Problems………………………………………………………………………………..220

Chapter 11 Shear Strength of Soils………………………………………………………….225

11.1 Introduction………………………………………………………………….225

11.2 Failure Criteria……………………………………………………………..225

11.3 Direct Shear Test…………………………………………………………..228

11.4 Unconfined Compression Test…………………………………………230

11.5 Triaxial Compression Test……………………………………………… 232

11.5.1 General Concept and Test Setup…………………………. 232

11.5.2 Initial Consolidation Process and Drainage

Condition during Shear……………………………………… 235

11.5.3 Consolidated Drained (CD) Triaxial Test……………..236

11.5.4 Consolidated Undrained (CU) Triaxial Test

with Pore Water Pressure Measurement……………….238

11.5.5 Effective Stress Parameters from CU and

CD Tests……………………………………………………….242

11.5.6 Unconsolidated Undrained (UU) Test…………………. 243

11.6 Other Shear Test Devices……………………………………………….244

11.6.1 Vane Shear Device…………………………………………….244

11.6.2 Tor-Vane Shear Test……………………………………………245

11.6.3 Pocket Penetrometer…………………………………………..245

11.7 Summary of Strength Parameters for Saturated Clays……….246

11.7.1 UU Test…………………………………………………………… 247

11.7.2 CD Test and CU Test (Effective Stress)……………….. 247

11.7.3 CU Test (Total Stress)……………………………………….. 247

11.8 Applications of Strength Parameters from CD, CU,

and UU Tests to In-Situ Cases…………………………………………248

11.8.1 Construction of Embankment on Soft Clay

Soil at Once (UU Case)………………………………………248

11.8.2 Foundation Design for Rapidly Constructed

Superstructures………………………………………………….248

11.8.3 Staged Construction of Embankment on Soft

Clay (CU Case)………………………………………………….248

11.8.4 Stability of Cut Slope (CD Case)………………………….249

11.9 Strength Parameters for Granular Soils……………………………250

11.10 Direction of Failure Planes on Sheared Specimen…………….. 252

11.11 Summary…………………………………………………………………….. 255

References…………………………………………………………………………….. 255

Problems……………………………………………………………………………….. 255

Chapter 12 Lateral Earth Pressure…………………………………………………………. 261

12.1 Introduction…………………………………………………………………. 261

12.2 At-Rest, Active, and Passive Pressures…………………………….. 261

12.3 At-Rest Earth Pressure………………………………………………….. 262

12.3.1 Elastic Solution………………………………………………….263

12.3.2 Empirical Formulae…………………………………………..263

12.4 Rankine’s Lateral Earth Pressure Theory…………………………265

12.4.1 Active Case……………………………………………………….265

12.4.2 Passive Case……………………………………………………..268

12.4.3 Summary of Rankine’s Pressure Distributions……… 271

12.5 Coulomb’s Earth Pressure……………………………………………… 276

12.5.1 Active Case………………………………………………………. 276

12.5.2 Passive Case……………………………………………………..277

12.5.3 Coulomb’s Lateral Pressure Distribution……………… 279

12.6 Lateral Earth Pressure Due to Surcharge Load………………… 281

12.6.1 Due to Infinitely Long Uniform Surcharge Load….. 281

12.6.2 Due to Point Load (Non-Yielding Wall)……………….. 281

12.6.3 Due to Line Load (Non-Yielding Wall)………………..282

12.6.4 Due to Strip Load (Non-Yielding Wall)………………..283

12.7 Coulomb, Rankine, or Other Pressures?…………………………..285

12.8 Summary……………………………………………………………………..288

References……………………………………………………………………………..288

Problems………………………………………………………………………………..288

Chapter 13 Site Exploration……………………………………………………………………. 295

13.1 Introduction…………………………………………………………………. 295

13.2 Site Exploration Program………………………………………………. 295

13.3 Geophysical Methods…………………………………………………….297

13.3.1 Ground Penetration Radar Survey……………………….297

13.3.2 Seismic Surveys………………………………………………..297

13.4 Borehole Drilling…………………………………………………………..299

13.4.1 Number of Borings…………………………………………….299

13.4.2 Depth of Boreholes…………………………………………….300

13.5 Standard Penetration Test……………………………………………….300

13.6 Undisturbed Soil Samplers……………………………………………..303

13.7 Groundwater Monitoring………………………………………………..305

13.8 Cone Penetration Test…………………………………………………….305

13.9 Other In-Situ Tests…………………………………………………………308

13.9.1 Vane Shear Test…………………………………………………308

13.9.2 Pressuremeter Test……………………………………………..308

13.9.3 Dilatometer Test………………………………………………..308

13.10 Summary……………………………………………………………………..309

References…………………………………………………………………………….. 310

Chapter 14 Bearing Capacity and Shallow Foundations…………………………… 311

14.1 Introduction…………………………………………………………………. 311

14.2 Terzaghi’s Bearing Capacity Theory……………………………….. 311

14.3 Generalized Bearing Capacity Equation………………………….. 312

14.3.1 Shape Factors fcs, fqs, fγs……………………………………… 313

14.3.2 Depth Factors fcd, fqd, fγd…………………………………….. 314

14.3.3 Inclination Factors fci, fqi, fγi……………………………….. 314

14.4 Correction Due to Water Table Elevation…………………………. 317

14.5 Gross versus Net Bearing Capacity…………………………………. 319

14.6 Factor of Safety on Bearing Capacity……………………………… 320

14.6.1 F.S. for Gross Bearing Capacity………………………….. 320

14.6.2 F.S. for Strength Parameters……………………………….. 321

14.7 Shallow Foundation Design……………………………………………. 321

14.7.1 Footing Depth…………………………………………………… 321

14.7.2 Design Method…………………………………………………. 322

14.8 Summary……………………………………………………………………..324

References……………………………………………………………………………..324

Problems………………………………………………………………………………..324

Chapter 15 Deep Foundations…………………………………………………………………. 327

15.1 Introduction…………………………………………………………………. 327

15.2 Types of Piles………………………………………………………………. 327

15.3 Load Carrying Capacity by Static Analytical Methods……… 327

15.3.1 Tip Area Ap and Perimeter of Pile “p”…………………. 330

15.4 Static Pile Capacity on Sandy Soils………………………………… 333

15.4.1 Tip Resistance………………………………………………….. 333

15.4.2 Skin Friction Resistance…………………………………….. 333

15.5 Static Pile Capacity in Cohesive Soils……………………………… 336

15.5.1 Tip Resistance………………………………………………….. 336

15.5.2 Skin Frictional Resistance………………………………….. 337

15.6 Other Methods of Pile Capacity Estimation……………………… 343

15.6.1 Pile Capacity from SPT and CPT Data…………………344

15.6.2 Pile Load Test……………………………………………………346

15.6.3 Pile Driving Formula…………………………………………349

15.6.4 Dynamic Pile Analysis………………………………………. 350

15.7 Negative Skin Friction…………………………………………………… 351

15.8 Group Pile……………………………………………………………………. 351

15.9 Consolidation Settlement of Group Piles…………………………. 354

15.10 Pullout Resistance………………………………………………………… 357

15.11 Summary…………………………………………………………………….. 357

References…………………………………………………………………………….. 357

Problems……………………………………………………………………………….. 358

Chapter 16 Slope Stability………………………………………………………………………. 363

16.1 Introduction…………………………………………………………………. 363

16.2 Slope Failure………………………………………………………………… 363

16.2.1 Slope Failure Modes………………………………………….. 363

16.2.2 Mechanism of Slope Failure………………………………. 363

16.2.3 Factor of Safety against Sliding…………………………..364

16.2.4 Factors of Slope Failure………………………………………365

16.2.4.1 Increases in Triggering Factors……………..366

16.2.4.2 Decreases in Resisting Factors………………366

16.2.5 Factor of Safety against Soil’s Strength………………..366

16.3 Slope Stability Analytical Methods…………………………………366

16.3.1 Limit Equilibrium Method…………………………………. 367

16.3.2 Short-Term and Long-Term Stability Analysis……… 367

16.4 Slope Stability of a Semi-infinitely Long Slope………………… 367

16.4.1 Dry Slope…………………………………………………………. 367

16.4.2 Slope under Steady Water Table…………………………..368

16.4.3 Slope with Water Flow Parallel to

Slope Direction………………………………………………371

16.4.3.1 Flow Surface at Slope Surface (h = z)……. 372

16.4.3.2 Flow Surface at Sliding Surface (h = 0)…….372

16.4.3.3 Flow Surface below Sliding Surface

with Consideration of Capillary

Rise (h < 0)………………………………………… 372

16.4.4 Slope with Horizontal Water Flow………………………. 372

16.4.5 Slope with Water Flow in θ Angle Direction

from Horizontal………………………………………………… 374

16.5 Stability Analysis for Circular Slip Surface……………………… 376

16.5.1 φ = 0 Materials (Cohesive Soils)…………………………. 376

16.5.2 c = 0 and φ Materials (Granular Soils)…………………. 377

16.5.3 c and φ Materials with Boundary Water Pressure…….379

16.5.4 Slice Method…………………………………………………….380

16.6 Analysis for Multiple Liner Sliding Surfaces……………………. 382

Contents xv

16.7 Stabilization for Unstable Slopes……………………………………..384

16.7.1 Change of Slope Shape……………………………………….384

16.7.2 Drainage of Water from Slope…………………………….384

16.7.3 Construction of Counterweight Berms…………………. 385

16.7.4 Retaining Wall Construction………………………………. 385

16.8 Summary…………………………………………………………………….. 385

References…………………………………………………………………………….. 385

Problems……………………………………………………………………………….. 386

Numerical Answers to Selected Problems…………………………………………………. 389

## Preface to the First Edition

Soil Mechanics Fundamentals is written with the intention of providing a very

basic yet essential concept of soil mechanics to students and engineers who are learning

the fundamentals of soil mechanics for the first time. This book is meant mainly

for college students who have completed key engineering science courses such as

basic calculus, physics, chemistry, statistics, mechanics of solids, and engineering

materials and are ready to enter into one of the specialty areas of civil, architectural,

and geotechnical engineering. This book is intended to provide a thorough, fundamental

knowledge of soil mechanics in a simple and yet comprehensive way, based

on the students’ knowledge of the basic engineering sciences. Special emphasis is

placed on giving the reader an understanding of what soil is, how it behaves, why it

behaves that way, and the engineering significance of such behavior.

There are many books on soil mechanics, geotechnical engineering, and the

foundation engineering field. Through our experience in teaching introductory

soil mechanics courses to college students for more than 20 years, we have come

to realize that most of these textbooks either lack comprehensive explanations of

soil behavior or contain massive information without clear and organized contents.

We have always felt the need for a better introductory textbook for our students. For

us, the ideal first textbook on soil mechanics should be presented with a firm basis of

the knowledge of the engineering sciences. First, the varied behavior of soils should

be well explained, based on mathematics, physics, and chemistry in a simple and

yet comprehensive way. Second, the rather complex phenomena of soil mechanics

should be better organized and presented in a systematic way with a smooth flow

of information. Last, students who have finished the first course of soil mechanics

should be ready to apply the learned concepts to field applications such as foundation

engineering with a full comprehension of the fundamentals of soil behavior.

In other words, students should not simply memorize equations and numbers, but

also understand why and how soil mechanics works. We believe that only then will

students and engineers confidently face challenging situations in well-thought-out,

logical, and innovative ways.

This book was written in such a way that the preceding ideal introduction of

soil mechanics concepts can be approached as closely and as smoothly as possible.

For example, plasticity of soils is rather easily understood after learning clay minerals

and the interactions of clay and water. Similarly, the quicksand phenomenon in

front of sheet pile and heaving at the bottom of excavation come after flow of water

and effective stress concepts. Also, Mohr’s circle is presented just before the shear

strength and lateral earth pressure theory. At the same time, we intentionally avoided

including too much information in each subject area. The same holds true for the

presentation of equations. There are always exceptions and there are many empirical

correlations available in the field of soil mechanics. However, this book includes only

the essential ones to emphasize the importance of fundamentals.

xviii Preface to the First Edition

To summarize, this book is not meant to cover the full spectrum of the geotechnical

engineering discipline, but rather to provide the simplest yet most comprehensive

first textbook in soil mechanics for students and engineers in the field of civil engineering

as well as architecture to understand what soil is, how it works, and why it

works that way.

## Preface to the Second Edition

The first edition of this book (Soil Mechanics Fundamentals) was published in

2010 with the aim to offer an introductory soil mechanics textbook to college students,

who for the first time would be exposed to this fascinating yet complex subject

area. The book was written with concise contents, yet with in-depth fundamental

principles on the subject. At the same time we tried to keep the cost of the book

affordable to the readers. The book has been well received all over the world, as

it explains soil’s fundamental behavior from basic engineering science knowledge

with carefully selected engineering practices and applications. Our original purpose

of the book has been accomplished and it has been well distributed around the world,

including a Japanese version published by Kyoritsu Publishing Company, Tokyo,

Japan. It has been adopted as a textbook in many institutions worldwide and has been

read by many practicing engineers.

On the other hand, we have received much input from the readers of the first

edition.

One of these suggestions was to expand the contents to include an introductory

foundation engineering section. We accepted this suggestion in order to

make the book a complete introductory geotechnical engineering book. Syllabuses

of many institutions cover the introductory foundation engineering concept after the

basic soil mechanics sections. This is our motivation for the second edition, Soil

Mechanics Fundamentals and Applications, and thus we kept the original first

12 chapters of soil mechanics without any major changes. Chapter 13 of the previous

edition was modified by adding the shallow foundation design section at the end,

and it became Chapter 14 (Bearing Capacity and Shallow Foundations) in this

new edition. Three new chapters on foundation-engineering-related topics have

been added: Chapter 13 (Site Exploration), Chapter 15 (Deep Foundations), and

Chapter 16 (Slope Stability).

Accordingly, the organization of the new edition of the book (which includes the

original 12 chapters) is as follows. Chapters and their contents are carefully placed

in an order so that the understanding level of the subject matter increases gradually

as we move from one chapter to another. Following the sequence presented in this

book is therefore recommended.

After the introductory Chapter 1 about soil mechanics, Chapter 2 (Physical

Properties of Soils) deals with the origin and the description of soils. The major terms

used in soil mechanics are defined by using the three-phase diagram. Soil shapes and

gradations are also discussed in this chapter. Chapter 3 (Clays and Their Behavior)

presents unique characteristics of clays from their mineral origins, sizes, shapes,

electrical properties, behavior in water, and interaction among particles. Based on

this knowledge, their plastic behavior, swelling, and shrinkage properties, sensitivity,

and quick clays are discussed.

Based on the information covered in Chapter 2 and Chapter 3, soil classifications by

the Unified Soil Classification System (also ASTM) and by the American Association

of State Highway and Transportation Officials (AASHTO) are presented in Chapter 4.

xx Preface to the Second Edition

Chapter 5 handles laboratory and field compaction techniques, including

description

of relative density and the CBR (California Bearing Ratio) method.

Chapter 6 presents the flow of water through soils. Definitions of various

hydraulic heads and the coefficient of permeability are presented, as well as the twodimensional

flow net technique, introduced from a simple one-dimensional water

flow mechanism without using the Laplace equation. Finally, a systematic method to

compute boundary water pressures is demonstrated.

In Chapter 7, the concept of effective stress and its applications to various

important

soil mechanics problems, including capillary rise, quicksand, and heave

at the bottom of an excavation, are discussed. The concept is later used in consolidation

theory (Chapter 9) and shear strength (Chapter 11).

Chapter 8 is a preparation chapter for Chapter 9 (Settlements). Stress increments

in a soil mass due to various types of footing load on the ground are presented. Most

of these solutions are based on Boussinesq’s elastic solution, and they are needed as

the major source of consolidation settlements in Chapter 9.

In Chapter 9, Terzaghi’s one-dimensional consolidation theory and its application

are presented. To simplify the discussions, the consolidation problems are categorized

into two parts: “how soon” (rate) problems and “how much” (amount of final

settlement) problems, so that readers can clearly avoid confusion while handling the

thickness (H or 2H) of the clay layer.

Chapter 10 deals with Mohr’s circle, which is utilized in chapters relating to shear

strength and lateral earth pressure. In particular, a clear definition of the shear stress

sign convention is made so that the concept of the pole of Mohr’s circle (the origin of

the planes) can be utilized effectively without any room for mistakes.

Chapter 11 is related to the shear strength of soils. Failure criteria are introduced,

and laboratory as well as field shear strength determination techniques are

presented. Clear definitions are presented on consolidated, unconsolidated, drained,

and undrained

shear strength parameters, and usages of these different shear strength

parameters are critically evaluated.

In Chapter 12, at-rest earth pressure and the classic Rankine and Coulomb active

and passive pressure theories are presented. These classic theories are critically

reviewed in terms of their assumptions and limitations, and appropriate applications of

the theories into practice are discussed.

Chapters 13 through 16 cover introductory foundation engineering. Chapter 13

is related to site exploration, which is needed prior to foundation design at given

sites. It includes a site exploration program, geophysical methods, borehole drilling

and sampling, and in-situ testing methods such as the standard penetration test, cone

penetration test, and other field test procedures.

Chapter 14 first presents the bearing capacity theory and, as an application, the

shallow foundation design procedure is described. Chapter 15 handles deep foundation

design procedures. Various analytical and field pile foundation design procedures

are presented. Negative skin friction, pullout resistance, group piles, and the

consolidation settlement are also discussed.

Finally, in Chapter 16, slope stability problems are presented. The mechanism

of slope failure, analytical methods for calculating the factor of safety, and slope

stabilization principles are discussed.

Preface to the Second Edition xxi

In most of the chapters, many exercise problems were carefully selected for

readers

to practice the use of the learned concepts. Spreadsheet techniques are often

employed in these exercise problems. At the end of each chapter, many problems

are selected, and they can be utilized by students to further exercise their skills in

problem solving, or they can be presented as homework assignments by instructors.

Numerical values of solutions for the problem sections are shown at the end of the

book for the convenience of self-study readers.

Throughout the book, key words are highlighted with bold letters and they also

appear in the subject index at the end of the book; thus, readers can easily search

the locations of these key words in the main section of the book. Some sentences

are highlighted with bold and italic letters, emphasizing the importance of the

concepts. References appear in bold and italic letters in the text and are listed at the

end of each chapter and in the author index at the end of the book.

This book basically uses SI units except the ones cited from original references.

For the measured weight unit, the gf (gram force) unit is used since it is commonly

the observed number on weighing balance. Thus, the value in gf units

should be multiplied by 0.00981 to obtain Newton force if needed. The key unit

conventions are also summarized and a unit conversion table appears on the back of

the front cover page.

Throughout the first as well as the second edition preparation processes, we have

received varying input, constructive review comments, and assistance from many

colleagues and friends from all over the world. We really appreciate the individuals

who supported and guided us. The following is a partial list of these individuals (in

alphabetical order of family names without titles): M. Sherif Aggour (United States),

Fauziah Ahmad (Malaysia), G. L. Sivakumar Babu (India), A. Boominathan (India),

Bodhinanda Chandra (India), Hiroshan Hettiarachchi (United States), Tatsuhisa

Hida (Japan), Yoshiaki Kikuchi (Japan), Taizo Kobayashi (Japan), Kunchithapatha

Madhavan (United States), Mohamed Mekkawy (United States), Achmad Muhiddin

(Indonesia), Mete Omer (United States), Kiyoshi Omine (Japan), Chuzo Tsuchiya

(Japan), Yoichi Watabe (Japan), Noriyuki Yasufuku (Japan), Yoshiaki Yoshimi

(Japan), and Askar Zhussupbekov (Kazakhstan).