GEOTECHNICAL ENGINEERING

(1)

A Practical Problem Solving Approach

N. Sivakugan I Braja M. Das

"-OOJ '.

'~

GeoStudio

.~

DVD INCLUDED

(2)

Geotechnical Engineedng/Civil Engineering

A Titlt in J Ross

Pubb~"lill[!,~'

Eureka Series

GeoSludio DVD INCLUDED

GEOTECHNICAL ENGINEERING

A Practical Problem 'Solving Approach

Nagaratnam Sivakugan & Braja M. Das

Geotechnical Engineering:

A Practical Problem Solving Approach covers all of the major .geotechnical topics in the simplest

possible way adopting a hands-on approach with a very strong practical bias. Engineers arc problem solvers.

Developing problem-solving skills is one of the key learning outcomes expected of engineering students and this book provides just that. 60-70% of the book is devoted to practical problem solving and 30-40% covers fundament.al concepts.

KEY FEATURES

• om'J"< carefully

^selected

solved problems with a wide range of difficulty level- from simple to challenging

• Includes a

DVD of th~

Student Edition of GeoStudio that can be used for solving a wide range of geotechnical problems

• Presents the material in the mosl

concise

manner

possible

while still including

enough

detail to solve

the

problems

• Demonstrates theory mrough practical problem wiving

\~~th

less

reliance

on

matbcrnatics

• om,r, both soil mechanics and [oandolion engineering in one book

• WYoffers downloadabk PowerPoint slides to assist in classroom instruc60n - available from the Web Added Value™ Download Resource

Center at

www.jrosspub.com

The

books

in ·theJ.

Ross

Publishing

Eweka Sen'es are

engineering

textbooks

for a new

gencl·ation. Similar

to

problell1~based

learn-

, ing~ ~he subject fnatenai 1S iritegrated "vith exten..<>;ive wurkf:cl ex·

amplet;, quizzes. and rcvic\\' exercises. The writing style is lean and simple while. not compromisiflg on the breadth or depth of

the

subject matter. Books in'the Eweka Selits are

written

by renowned scholars \vith outstanding university careers who have also made significant

contribuliom to teaching

and

leaming.

JR0167

IS8N: 978-1-60427-010-7

III III

⁹⁰⁰⁰⁰

9 781604 270167 1II1111111111111

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GEOTECHNICAL ENGINEERING

A Practical Problem Solving Approach

N. Sivakugan I Braja M. Das

J.~OSsJ

lPUBLISHING

(4)

J.

Ross Publishing. Inc.

ISBN-13: 978-l-60127-01 6-7

Printed and bound in the U.S.A Printed on acid-free paper

Library of Congress Cataloging-in-Publication Data Sivakugan, Nagaratnam, J 956-

Geotechnical engineering:

a practical problem solving approach

I by Nagaratnam Sivakugan and Braj.

M.

Das.

p.em.

Includes bibliographical references and index.

ISBN 978-1-60427-016-7 (pbk. : alk paper)

1. Soil mechanics. 2. Foundations. 3. Earthwork. l. Das. Braja M .•

TA710.S5362009

621.1' 5136-dc22

2009032547

This publication contains information obtained from authentic and highly regarded sources. Reprinted material is used with permission. and sources are indicated. Reasonable effort ha., been made to publiili reliable data and information, but tbe author· and the publi>her cannot assume responsibility for the validity o~ all materials or for tbe consequences of tbeir uSe.

All

rights reserved. Neitber tJm; publication nor any part thereof may

be

reproduced, stored in

a

retrieval system, or transmitted in any form or by any means, electronic. mechanical, photocopying, recording or otherwise. without the prior written permi>sion of the publisher.

The copyright owner's consent does not extend to copying for general distribution for promotion, for creating new work.. ^GTfor r""ale. Specific permission must be obtained from

J.

Ross Publishing for such purposes.

Direct all inquiries to

J.

Ross Publishing, Inc., 5765 N. Andrews Way, fort Lauderdale. FL 33309.

Phone: (954) 727-9333 Foci: (561) 892-0700 Web: ,,'ww.jrosspub.com

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Review

Exercises ... 71

Chapter 6 Permeability and Seepage ... 73

6.2 Bernoulli's Jiquation ... 73

6.3 Darcy's Law ... 76

6.4 Laboratory and field Permeability Tests ... 77

6.5 Stresses in Soils Due to Flow ... 81

6.6 Seepage ... 82

6.7 Design of Granular Fiiters ... 86

6.8 Equivalent Permeabilities for One·dimensional Flow ... 87

6.9 Seepage AnalYSis U,ing SEEPIW ... 89

Re\~ew Exercises ... 103

Chapter 7 Vertical Stresses Bene.th Loaded Are ... 115

7.1 lntroduclion ... 115

7.2 Stresses Due to Point Loads ... 116

7.3 Stresses Due to Line Loads ... " ... 118

7.1 Stresses Under the Comer of a Uniform Rectanl,'lllar l.oad ... 118

7.5 2:1 Distribution Method ... 123

7.6 Pressure Isobars Under Flexible Uniform Loads ... 124

7.7 Newmark's Chart.. ... 124

7.8 Stress Computations Using SIGMA/W ....... 129

Worked Examples.. ... 133

Chapter 8 Consolidation ... 139

8.1 Introduc(ion ... , ... \39

8.2 One-dimensional Consolidation ... 140

8.3 Consolidation Test ... 143

8.4 Camputation of Final Consolidation Settlemeot. ... 150

8.5 Time Rate of Consolidation ... , ... 153

8.6 Secondary Compression ... 159

Worked E.,.mplcs ... 165

Review Exec\:lscs ... __ _ ... , ... , ... .,._,. ... 175

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Contents vii

ChapteJ' 9 Shear Strength ... 181

9.2 Mohr Cirdes ... 11>1 9 .3 Mohr-Coulomb Fail" re Criterion ... 186

904 A Common Loading $ltuation ... 187

9.5 Mohr Cirdes and Failure Envelopes in Terms

of"

and 'T ... 190

9.6 Drained and Undrained Loading Situations ... 191

9.7

Triaxial

Test ... 193

98 Direct Shear Test... .. ... 200

9.9 Skempton's Pore Pressure Parameters ... 202

9.10 O'J

-(1,

Relatiollship at I'ailure ... 205

9.11 Stress Paths ... 206

Worked Examples ... 21 0 I(eview Exercises ... 217

Chapter 10 Lateral Earth Pressnres ... 225

10.2 At·rest State ... 226

10.3 Rankine's Earth Pressure Theory ... 230

lOA Coulomb's Earth Pressure Theory ... 237

Worked E~amples ... , ... , ... 210

Chapter 11 Site Investigation ... , ... 251

11.2 Drilling arid Sampling ... .253

11.3 In Situ Tests ... , .. " ... 257

1104 Laboratory Tests ... 276

11.5 Site Investigation Report... ... 276

Chapter 12 Shallow Foundalions ... 289

12.1 Introduction ... , ... 289

12.2 Design Criteria ... 290

12.3 Bearing Capacity of i\ Shallow Foundation ... 291

12.4 Pressure Distributions Beneath Eccentrically Loaded Footings ... 30J 12.5 Introduction to Raft Foundation Design ... 304

12.6 Settlement in a Granular Soil ... 310

12.7 Settlement in a Cohesive Soil ... 319

Worked Ex.mples ... 325 Review Exercises ... , ... 33'1

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Vlii Contents

Chapter 13 Deep Foundatinns ... _ ... 341

13.2 Pile Materials ... _ ... 342

13.3 Pile Installation ... _ ... 345

13.4 Load Carrying Capacity of a Pile-Static Analysis ... 347

13.5 Pile-Driving Formulae ... 354

13.6 Pile Load 'fest ... , ... " ... ~ .. ~ ... " .... ".,,.,--.. -<"H.,~ .. ~.' ... ,, •..•. ... <0"" ... " ... ; 0 " • • ," . • . • , . , , . . . 355

13.7 Settlement of a Pile ... 357

13.8 Pile Group ... 361

Worked E.xamples ... " ... .365

Review Exercises ... " ... 373

Chapter 14 Earth Retaining Sttuctures ... m . . . 377

14.2 Design of Retaining Walls ... 379

14.3 Cantilever Sheet Piles ... 385

14.4 Anchored Sheet Piles ... , ... 395

14.5 Braced ExcavatiOllS ... , ... 399

WOTked Examples ... .404

Review £xercises ... 415

Chapter 15 Slope Stability ... 421

15.2 Slope Failure and Safety Factor ... 422

15.3 Stability of Homogeneous Undrained Slopes ... 423

15.4 Taylor's Stability Charts for c'

-q,'

Soils ... 427

15.5 Infinite Slopes ... , ... ..429

15.6 Method of Slices ... , ... 432

15.7 Stability Analysis Using SLOPE/W ... 435

Worked Examples ... .443

Review Exerdses ... 449

Chapter 16 Vibrations of Fowtdations ... .453

16.1 Introduction ... m ... .453

16.2 Vibration Theory-General ... , ... .454

16.3 Shear Modulus and Poisson's Ratio ... 463

16.4 VeTtical Vlbration of Foundations- Analog Solution ... _ ... , ... , ... .465

16.5 Rocking Vibration of Foundations ... , ... .469

16.6 Sliding Vibration of Foundations ... _ ... , ... 475

16.7 Torsional Vibration of !'oundations ... 478

Review Exercises ... , ... .483

Index ... · .. · .. · ... • ... , ... 487

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Preface

We both have been quite successful as geotechnkal engineering teachers. In Geotechnical Engi- neering: A Practical Problem Solving Approach, we have tried to cover every major geotechnical topic in the simplest way possible. We have adopted a hands-on approach with a stCGng, practical bias. You willlcam the material through several worked examples that take geotechnkal engineering principles and apply them to realistic problems that you are likely to encounter in real-life field situations. This is our attempt to write a straightforward, no-nonsense, geotechnical engineering textbook that will appeal to a new generation of students. This is said with no disrespect to the variety of geotechnical engineering textbooks already available---each serves

a purpose. .

~~ ^'f'

We have used a few symbols to facilitate quick referenciug and to call your at- ... rj):

tention to key concepts. This symbol appears at the end of a chapter wherever it is·",,; ..

necessary

to

emphaSize a partkular point and your need to understand it. ~ern' del'

There are a few thoughtfully selected review exercises at the end of each chap- '"

tec, and answers are given whenever possible. Remember, when you practice as a professional engineer you will not get to see the solutions! You will simply design with confidence and have it checked by a colleague. The degree of difficolty in- creases with each review exercise. The symbol shown here appears beside the most challenging problems.

We also try to IHLrturC the habit of self-learning through exercises that re- late to topks not covered in this book. Here, you are expected to surf the Web; or even better, refer to library books. The knowledge obtained from both the research activity and the material itself will complement the mate-

rial from this book and is an integral part of learning. Such research-type

questions are identified by the symbol shown here. Today, the www is at your fingertips, so this should not be a problem. There are many dedicated Web sites for geotechnical re- sources and reference materials (e.g., Center for Integrating Information on Geoengineer- ing at http://www.geoengineer.org). Give proper references for research-type questions in your short essays. Sites like Wildpedia (http://en.wikipedia.org) and YouTube (http://www .youtube.com) can provide useful information including images and video clips. To obtain the best references, you mnst go to the library and conduct a proper literature search using appro- priate key words.

ix

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x Preface

We have included eight quizzes to test your comprehension, These are closed- book quizzes that should he completed within the specified times, They are de-

sigll~d to make you think and show you what YOll have missed,

The site investigation chapter has a slightly different layout. lhe nature of this topic is quite descriptive and less rejiant on problem solving. It is good to have a dear idea of what the different in situ testing devices look like. For

this

reason, we have induded several quality photographs. The purpose of the site investigation exercise is to derive the soil pa rameters from the in situ test data. A wide range of empirical correlations that are used in practice are summarized in this chapter. Tests are included that are rarely covered in traditional textbooks-such as the borehole shear test and

the Ko

stepped blade test-and are followed by review questions that encourage the reader to review other SOurces of literature and hence nurture the habit of research.

Fotmdation Engineerlng is one of the main areas of geotechnical engineering; therefore, considerable effort was directed toward Chapters 12 and 13. which cover the topics of bearing capacity and settlements of shallow and deep foundations.

This is not a place for uS to document everything we know in geotechnical engineering, We realize

that

this is your first geotechnical engineering book and have endeavored (0

give

sufficient breadth and depth covering

all

major topiCS in soil mechanics and foundation engineering.

A free DVD containing the

Student Edition

of

GeoStudio

is included with this book. It is

a

powerful software suite that can be used for solving a wide range of geotechnical problems and

is a

useful complement to traditional learning.

We are

grateful to

Mr.

Paul Bryden and the GeoStudio team for their advice and s~lpport.

We

are grateful LO the following people who have contributed either by feviewing 'hapters from the book

and

proViding suggestions for improvement Dr. Jay Amcratunga. Colfey Geo- technics; Ms. Julie Lovisa. James Cook University; Kieralee Rankine, Golder Associates; and Shailesh Singh, Colfey Gcotechnks; or by providing photogr~phs or data: Dr. Jay Ameratunga, Coffey Geotechnics; Mr. Mark Arnold, Douglas Parlners;

Mr.

Martyn Ellis, PMC. UK; Profes- sor Robin Fell, University of New South Wales; Dr. Chris Haberfield. Golder Associates; Profes- sor Silvano Marchetti, University of LAquila, Italy; Dr. Kandiah Firapakaran, ColTey Geotech- nics:

Dr.

Kirralee

Rankine,

Golder Associates; Dr.

Kelda

Rankine. Golder Associates;

Dr.

Ajant.

Saehan.lIT Kanpur. India: Mr. Leonard Sands, Venezuela; Dr. Shailesh Singh, ColIey Geotech- nics; Mr. Bruce Stewart, Douglas Partner.; Professor David White, Iowa State University.

We wish to thank Mrs. Janke Das and Mrs. Rohini Siwkugan, who provided manuscript preparation

and

proofreading assistance. Finally, we wish to thank Mr. Tim Pletscher of). Ross Publishing for his prompt response to

all

our questions and

for his

valnable contributions at various

stages.

N. Sivakugan and B. M. Das

GEOTECHNICAL ENGINEERING - James Cook University