Table Of ContentAN INTRODUCTION·.TO .·
GEOTECHNICAL ENGINE.ERING
Second Edition
Robert D. Holtz, Ph.D., P.E., D.GE
University of Washingt()n
William D. Kovacs, Ph.D., P.E., D.GE
. University of Rhode Island .. ·
Thomas C. Sc.D.,' P.E.
Sheahan~
Northeastern University · ·
PEARSON
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Library of Congress Cataloging-in-Publication Data
Holtz, R. D.. (Robert D.)
An introduction to geotechnical engineering I Robert D. Holtz, William D. Kovacs, Thomas C. Sheahan.--2nd ed.
p.cm.
Includes bibliographical references and index.
ISBN 978-0-13-031721-6 (alk. paper)
1. Soil mechanics--Textbooks. 2. Rock mechanics--Textbooks. I. Kovacs, William D. II. Sheahan, Thomas C. III. Title.
TA710.H564 2011
624.1'51--dc22 2010028254
Prentice Hall
is an imprint of
10 9 " 8 7 6 5 4 3 2 1
PEARSON
·rsB~-13: 978-d-13-249634-6
· www.pearsonhighered.com ISBN~10: 0-13-249634-8
(p 7.-t.( •151 3
H7Lf5.i
~t'J I),
Contents
Preface viii
Chapter 1 Introd~ction to:<Jeotec~nicalEngineering. 1
1.1 Geotechnical Engineering. 1
1.2 The Unique Nature of Soil and Rock Materials 3
1.3 Scope of this Book · · '4 : 1 : • ' : ''; 1 ' • .• · • •
1.4 Historical Development of Geotechnical' Engineering... , 5 .
1.5 Suggested Approach to the Study of Geotechnical Engineering . 6
1.6 Notes on Symbols and Units 6, ·· .·.
1.7 Some Comments on.How to Study in GeneraL .. .7; ..
Problems 8 · · · · · ·· · · .
Chapter 2 Index and Classification Properties of Soils .· ·· · 9.
• • " ' • . . ~ ' l • . ' •• ,' . ' ' ' • ' ~ • • ':. ' ; ' • ' ' -•
:l: ·;
2.1 Introduction •' · 9
2.2 Basic Definiti~ns and Phase Relations for Soils ·· 10''
2.3 S~lution of Ph~se Problems 15
2.4 SOil Texture 31-' :·;'
2.5 Grain Size and Grain Size Distribution .. · 32
2.6 Particle Shape 39
2.7 Atterberg Limits @) · :
2.8 Introduction to Soil Classification .47
2.9 Unified Soil Classification System(USCS). 48·.·
2.10 AASHTO Soil Classification System·. 61
Problems · 61 ' · ·. · · · · · ·. · ·
. . ' 69
Chapter 3 Geology, Landforms, and the Origin of Geom.aterials ,
3.1 Importance of Geology to Geotechnical Engineering · · 69
3.2 The Earth; Minerals, Rocks, and Rock Structure 71 · · ,
3.3 Geologic Processes and Landforms 76
3.4 Sources of Geologic Information 117
Problems 119
iii
iv Contents
Chapter 4 Clay Minerals, Soil and Rock Structures, ·
and Rock Classification 122
4.1 Introduction 122
4.2 Products of Weathering 122
4.3 Clay Minerals 123
4.4 Identification of Clay Minerals and Activity 131
4.5 Specific Surface 133
4.6 . Interaction Between Water and Clay Minerals 134
4.7 Interaction of Clay Particles 138
139
4.8 Soil Structure and Fabric of Fine-Grained Soils ·
4.9 Granular Soil Fabrics 147
4.10 Soil Profiles, Soil Horizons, and Soil Taxonomy 150.
4.11 Special Soil Deposits 151
4.12 Transitional Materials: Hard Soils Versus Soft Rocks 152
4.13 Propertie~, Macrostnicture, a~d Classification of Rock Masses 154
Problems 161
Chapter 5 Compaction and Stabilization of Soils • 163
5.1 Introduction · 163
'.
5.2 Compaction and Densification ·. ' 164 .
5.3 Theory of Compaction for Fine~Grairied Soils · · 164 ·
5.4 Structure. of Compacted Fine~GraineciSoils · · 172
5.5 Compaction of Granular Soils 173
5.6 Field Compaction Equipment and Procedures 178
5.7 Specifications and Compaction Control' · '190 ··'
5.8 Estimating Performance of Compacted Soils .. •2 06 ·
Problems 210 .... :.
Chapter 6 Hydrostatic Water in Soils and Rocks 214,
6.1 Introduction 214
6.2 Capillarity 215
6.3 Groundwater Table and the Vadose Zone .· · 227
6.4 Shrinkage Phenomena in Soils 230. · · · ·
6.5 Expansive Soils and Rocks· · · · 236 ' .
6.6 Engineering Significance'of Shrinkage and Swelling 244
6.7 Collapsible Soils and Subsidence 246
6.8 . Frost Action 249 · .
6.9 ' Intergranular 'or Effective Stress 257 I ; ~
6.10 · Vertical Stress Profiles 262
6.11 RelationshipBetween Horizontal and Vertical Stresses , ·· 266
Problems 267
Contents v
Chapter· 7 Fluid Flow in Soils and Rock. · · 272
7.1 Introduction 272
7.2 Fundamentals ofFluidHow 273
7.3 Darcy's Law for Flow Through Porous Media· ·. . 275
7.4 Measurement of Permeability or Hydraulic Conductivity 277
7.5 · , Heads and One-Dimensional Flow · 285 ·. · •·. ·
7.6 Seepage Forces, Quicksand, and Liquefaction '294
7.7 Seepage and Flow Nets: Two-Dimensional Flow 306 · ·
7.8 Seepage Toward Wells. 321 .
7.9 'seepage Through Dams and Embankments · 325
7.10 Control of Seepage and Filters 327 ·
Problems · 338 ,
Chapter 8 Compressibility of Soil an~ Rock 345
8.1 Introduction 345
•8 .2 Components of Settlement 347
8.3 · Compressibility of Soils . 347 ·
8.4 One-Dimensional Consolidation Testing 350
8.5 Preconsolidation Pressure and Stress History 352
of
8.6 · Consolidation Behavior Natural and Compacted Soils · 357
8.7 Settlement Calculations 364
8.8 Tangent Modulus Method .· 377 " , . , ..
'·
8.9 Factors Affecting the Determination of a~ 380. ·
8.10 Prediction of Field Consolidation Curves · · 380
8.11 ' • Soil Profiles . 388 • . · ' . · · ,
'8.12 Approximat~ Methods a~d Typi~al Values of Comp~ession Indices 394
8.13 Compressibility of Rock andTransitionalMaterials , . 395
8.14 Burland's Intrinsic Compressibility Properties 395
8.15 In,Situ Determination.of,Compr~ssibil~W.·. ·· .. 398 · ... ·.·
Problems 399 ·
Chapter 9 · Time R~ti of Corisolidatib~ ·: .·, 404
9.1 ' Introduction . · 404
9.2 The Consolidation Process 405
9.3 Terzaghi's One-Dimensional Consolidation Theory · 407
9.4 Determination of the Coefficient of Consolida'tion Cv. •• 427 :
9.5 , Determination of the Coefficient of Permeability ·. •· 432
9.6 Typical Values of the CoeffiCient of Consolidation c~ 433 .·
9.7 In Situ Determination of Consolidation Properties -434
9.8 Evaluation of Secondary Settlement · •• •4 35 · · '
Problems 442
/
vi Contents
Chapter 10 Stress Distribution and Settlement Analysis, • 450 . ·
10.1 Introduction 450 ,, •
10.2 Settlement Analysis of Shallow Foundations .· · • 451
10.3 Stress Distribution .. 454 • :·: , .; .
10.4 Immediate Settlement : 472;: .. •. .
10.5 Vertical Effective Overburden and Preconsolidation Stress Profiles 477
. . .
10.6 Settlement Analysis Examples 479,: , .
i. :·
Problems 492 ·
Chapter 11 The.Mohr Cirde, Failure Theories;'~~cl Str~engthTesting
of Soil and Rocks 497: l, · ·,,
11.1 Introduction 497
11.2 Stress at a Point · 498 . . . · · .· ..
11.3 Stress-Strain Relationships·and Failure Criteria : · 507 ·
11.4 The Mohr-Coulomb Failure Criterion · 508
11.5 Laboratory Tesfs for the Shear Strength of Soils and Rocks · 516
11.6 In Situ Tests for the Shear Strength of Soils and Rocks . 526
Problems. . . 536 : ,, ·. : :: ·. ·
.-.,
~ /'- ~ ' " ' ' ' '
Chapter 12 An Introduction to ShearStrengthof Soils and Rock. 540
12.1 Introduction 540 :.: ' · :
12.2 Angle of Repose of Sands • 542 · . .
12.3 Behavior of Saturated Sands During Drained Shear 543
on
12.4 Effect of Void Ratio and Confining Pressure Volume Chan.ge 545
12.5 . Factors that Affect the Shear Strength ofSands ·. .5 53 . . .
• 12.6 Shear Strengthof SandsUs ing In SituTests : .· 1.558 ··. . .
12.7 The CoeffiCient of Earth Pressure at'Restfor Sands' : ,· 560
12.8 BehaviorofSatunited'coh.'esive Soils Du'rin'g 'shear·· ··•·.'563
12.9 Consolidated-Drained Stress~ Deformation .and Strength ·
Characteristics 564 · · · ' ; '
12.10 Consolidated-Undrained Stress-Deformation,and Strength ..
Characteristics ·' 570 ·• '· • · ' '' · · ::• ·
12.11 Unconsolidated-Undrained Stress-Deformation and Strength;, .
Characteristics 578 . ·. · , ,
12.12 Sensitivity • 591 .
12.13 ·.The Coefficient of Earth Pressure at Rest for Clays.; .. , 592
12.14 Strength of Compacted Clays . · 596 ·
12.15 . Strength of Rocks and Transitional Materials . . 600
12.16 Multistage Testing 601, .. , <
12.17 Introduction to Pore Pressure Parameters . 606 • .
Problems 610
.,
Contents vii
Chapter 13 Advanced Topics in Shear Strength of Soils and Rocks 614
13.1 Introduction 614
13.2 Stress Paths 616
13.3 Pore Pressure Parameters for Different Stress Paths 627
13.4 Stress Paths During Undrained Loading_:Normally and Lightly
Overconsolidated Clays · 629' · ·
13.5 Stress Paths During Undrained Loading-Heavily
Overconsolidated Clays 644 ··
13.6 Applications of Stress Paths to Engineering Practice 647
13.7 Critical State Soil Mechanics · 652 ·
13.8 Modulus and Constitutive Models for Soils 663
13.9 Fundamental Basis of the Drained Strength of Sands 675
13.10 Behavior of Saturated Sands in Undrained Shear 682
13.11 Plane Strain Behavior of Sands 696
13.12 Residual Strength of Soils 702 · ··
13.13 · Stress-Deformation and Shear Strength of Clays: Special Topies · 705
13.14 · Strength of Unsaturated Soils 731 ·
13.15 Properties of Soils Under Dynamic Loading 737
· 13.16 Failure Theories for Rock 750
Problems 754
Appendix A · Application of the SI System of Units
to Geotechnical Engineering 765
.Appendix 8.1 Derivation ofLaplace's Equation 778
Appendix 8.2 Derivation arid Solution of Terzaghi's .
One-Dimensional Corisolidatiori TheorY · 780
· Appendix 8.3 ·· Pore Pressure Parameters 786 ·
Appendix( .· · The .Method of Fragme~ts 795 ·
References 806
•. .
Index 840
Preface
,•'t_,
It has been thirty years since the publication of the first edition of An Introduction to Geotechnical
Engineering. During those years, the practice of geotechnical engineering has greatly changed, but the
fundamentals of soil mechanics and soil properties have remained essentially the same. Engineering
·education also has changed during that time, mostly for the better. On the other hand, reduced gradu~
ation requirements and the increased use of computations instead of the laboratory experience have
often resulted in a tendency toward reduced rigor arid over-simplification of some undergraduate edu-
cation and textbooks. · · ·
. We still believe that there is.· a need for more detailed. and moder~· coverage. of the engineering
properties of geo-materials than is found in most undergraduate texts. This applies to students who
concentrate in geotechnical engineering as well as the general civil engineering undergraduate student.
Our students will be involved in increasingly more complex projects, esp_ecially those in transportation,
structural, construction and 'environmental engineering.' Those projects will increasingly involve envi
ronmental, economic and political constraints that will demand innovative solutions to civil engineer
ing problems. Modern analytical techniques using digital computers have had a revolutionary effect on
engineering design practice. However, the validity of the results from these computational procedures
(which typically include 'striking graphical output) is highly dependent on the quality of the geotechni-
. cal engineering design parameters as well as the geology and site conditions. . . . .
Like the first edition, this ~dition is intended for use in the first of a two-~ourse sequence in geotech
to
nical engineering usuallytinight third~ and fourth~yea~ undergraduate civil engineering students. We
· assume the students have a working knowledge of undergraduate mechanics, especially statics and
mechanics of materials, including fluids. In the first course we introduce the ''language" of geotechnical
engineering-that is, the classification and engineering properties of soils and rocks. Once the student
has a working knowledge of the behavior'of geo-materials, he/she can begin to 'predict soil behavior
and, in the second course, carry out the design of simple foundations and earth structures.
We have tried to make the text easily readable by the average undergraduate. To this end, An
Introduction to Geotechnical Engineering is written at a rather elementary level, although the material
covered may at times be quite sophisticated and complex. Involved derivations are relegated to appen
dices, where they are available to the interested student.
·The emphasis throughout is on the praCtical, and admittedly empirical, knowledge of soil and
rock behavior required by geotechnical engineers for the design and. construction of foundations,
embankments, and underground structures. Most of the material in the text is descriptive, since most of
the engineering design applications are usually left to the second course in foundation engineering.
Consequently, in order to strengthen this connection between the fundamental and applied, we have
tried to indicate wherever possible the engineering significance of the property being discussed, why the
property is needed, how it is determined or measured, and, to some extent, how it is actually used in spe
cific design applications. We illustrate some simple geotechnical designs-for example, determining the
viii
Preface ix
··flow, uplift pressures;and exit gradients in•2-D seepage problems, and estimating the settlement of
shallow foundations on sands and saturated clays. . ' ' .
· One thing that has not changed in thirty years is tliat units remain a problem with U.S. geotech
nical'engineers. In line with the rest· of the world, the 'American Society of Civil Engineers, and the
American Society for Testing and Materials, we have used the S.l. System of Units in the text. Most stu-
, dents are conversant in both the U.S. customary (or British) engineering units and S.l., but readers
unfamiliar with S.l. may find Appendix A helpful. We have examples and problems in both systems,
and we have been careful to use the correct definition of density (mass/unit volume) in phase relation-
ships as well as in geostatic and hydrostatic pressure computations. ·
We consider the laboratory component of the first course to be an essential part of the neophyte
. engineer's experience with soils as a unique engineering material. How else is the young engineer to begin
:' to develop a "feel" for soils and soil behavior, so essential for the successful practice of geotechnical engi
.. neering? An emphasis on laboratory and field testing is found throughout the text. The organization and
development of the material iri the text is traditional and generally follows the order of the laboratory por
tion of our first courses. The early chapters introduce the discipline of geotechnical engineering, phase rela
tionships, index and classification properties of soils and rocks, geology, landforms, and the origin of
geo-materials, clay minerals, soil and rock structures, and rock classification. Chapter 3, "Geology, Land~
forms, and the Origin of Geo-Materials," has been added to this edition because these topics are so critical
·. to understanding the properties and subsequent behavior of geo~materials under. various loading condi
.. tions. These chapters provide the background and terminology for the remainder of the text..
· .. ·Following a very practical discussion of compaction in Chapter 5, Chapters 6 and 7 describe how
;.;
water influences. and affects soil behavior. Topics presented in Chapter 6 include groundwater and
vadose water, capillarity, shrinkage, swelling, and. collapsing soils; frost· action, and effective stress.
Chapter 7 discusses permeability, seepage, and seepage control.· , . · · .
. The last six chapters deal with the compressibility and shear strength of soils and rocks. The
treatment of these topics is quite modern and has been updated considerably. We now have stress dis
tribution and settlement analyses, including immediate settlement, in. a: new ChapterlO to separate
these practical procedures from the more basic time-rate and compressibility behavior of natural and
· , , compacted soils and rock,masses described in Chapters 8 and 9. In these latter chapters we have
. ,included new material on Janbu's tangent modulus method, in situ determination of compressibility of
soil and rock, Burland's intrinsic compressibility of soils, and finite difference solution to the Terzaghi
.c onsolidation equation. We have extended. the. Schmertmann method for prediction of field compres
sion curves to overconsolidated soils, and we have updated Mesri's work on secondary compression.
We received much criticism about the length of Chapter 11 on shear strength in the first edition,
so now shear strength properties of soils and rocks are discussed in three new chapters. New Chapter 11
.o n the Mohr circle, failure theories; and strength testing of soil and rocks has new material on the obliq
uity relations and in situ tests for shear strength. Chapter 12 is an introduction to shear strength of soils
and rock and is primarily suitable for undergraduate students. More advanced topics in shear strength of
soils and rocks are discussed in Chapter 13, which graduate students and practicing geotechnical engi
.neers should find useful. New material in Chapter·12jncludes multistage testing, in situ tests for the
. shear strength of sands and the strength of compacted clays, rocks, and transitional materials. We now
..h ave the stress-path method in Chapter 13, which also includes sections on critical-state soil mechanics
and an introduction to constitutive models. We then discuss some advanced topics on the shear strength
: .· of sands that start with the fundamental basis of.their drained, undrained, and plane-strain. strengths.
•. The residual shear strength of sands and clays provides a transition into the stress-deformation and
. 'shear strength of clays, where we discuss failure definitions, Hvorslev strength parameters, stress history,
:the·· Jurgenson-Rutledge hypothesis, consolidation methods.· to overcome sample . disturbance,
anisotropy, plane-strain strength, and strain-rate effects. We .. end. Chapter 13 with sections on the
. strength of unsaturated soils, properties of soils up.der dynamic loading, and failure theories for rock.
x Preface
Even though it is primarily for the beginning student in geotechnical engineering, advanced stu
dents in other disciplines and engineers desiring a refresher in engineering properties may find the
book helpfuL Because of the many fully worked example problems, the book is almost "self-teaching."
This aspect of the text also potentially frees the instructor in a formal· course from the necessity of
working example problems during lectures. It allows the instructor to concentrate on explaining basic
principles and illustrating specific engineering applications of the points in question. From the first edi
tion, we know that many practicing geotechnical engineers will find this book useful as a refresher and
for the typical v~lues given for classification and engineering properties for a wide variety of soils; we
have found such a compendium very useful in our own engineering practice. ·
The solutions manual and test manual as well as PowerPoint figures of all images and tables
from this book can be downloaded electronically from our Instructor's Resource Center located at
www.pearsonhighered.com. The material available through the Instructor Resource Center is provided
solely for the use of instructors in teaching their courses and assessing student learning. All requests for
instructor access are verified against our customer database and/or through contacting the requestor's
institution. Contact your local sales representative for additional assistance or support.
ACKNOWLEDGMENTS
To acknowledge all who have contributed to this book is a formidable task. We have tried whenever
possible to indicate by references or quotations, concepts and ideas originating in the literature or with
our former teachers, especially Profs. B. B. Broms, A. Casagrande, R. J. Krizek, C. C. Ladd, J. K. Mitchell,
J. 0. Osterberg, and H. B. Seed. Others have made helpful suggestions or reviewed portions of the text,
resulting in improvements to the final pr'oduct. These include Roy Borden, David Chang, Herbert
Einstein, Milt Harr, Vic Kaliakin, Jerry Leonards, Bill Likos, Harry Stewart, Dayakar Penumadu, Siva
Sivakugan, and Tom Zimmie, and countless others who have made comments about the first edition
over the years. The comments of Dick Galster; Teresa Taylor, and Hank Waldron significantly improved
· early drafts of Chapter 3. .. · · ·
· We'are grateful to our Production Project Manager, Clare Romeo, for the patience, diligence and
humor she exhibited in the face of many challenges, imd for her help in ensuring the quality of the fmal
product. We also acknowledge those who assisted in the development of the 2nd edition through contribu
tions of figures, reports, and administrative assistance. Figures and other resources were graciously supplied
by John Burland, Don DeGroot, and Paul Mayne, among others·from the 1st edition. At·Northeastern,
·Joan Omoruyi, Ed Stevens, and Brett McKiernan provided research and administrative assistance.
Thank you to the reviewers of this edition: Kamal Tawfiq, Florida State University; Monica
Prezzi, Purdue University; Jay DeNatale; California Polytechnic State University; Robert Mokwa,
Montana State University; Balasingam Muhunthan, Washington State University; Trevor Smith, Port
land State University; Tom Zimmie; Rensselaer Polytechnic Institute; Scott Ashford, University of
California:...san·Diego; Robert D'Andrea, Worcester Polytechnic Institute; Samuel Clemence, Syracuse
University; Dave Elton, Auburn University; and Khaled Sob han, Florida Atlantic University.
· On a personal note, we wish to thank our respective spouses, ·cricket, Eileen and Maryrose, who
endured from a few to several years of delays, sporadic periods of stress, and many evenings and week
ends that should have been spent with their husbands instead of sharing their marriages with this book.
R.D.HOLTZ
SEATTLE, WASHINGTON
W.D.KOVACS
KINGSTON, RHODE ISLAND
T. C. SHEAHAN
BOSTON, MASSACHUSETTS
