GEOTECHNICAL ENGINEERING: PRINCIPLES AND PRACTICES Second Edition GEOTECHNICAL ENGINEERING: PRINCIPLES AND PRACTICES Second Edition | | Donald P. Coduto California State Polytechnic University, Pomona Man-chu Ronald Yeung California State Polytechnic University, Pomona -. William A. Kitch California State Polytechnic University, Pomona - Upper Saddle River Boston Columbus San Francisco New York Indianapolis London Toronto Sydney Singapore Tokyo Montreal Dubai Madrid HongKong Mexico City Munich Paris Amsterdam Cape Town Vice President and Editorial Director, ECS: Cover Iustration/Photo(s): Marcia J. 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Copyright © 2011 by Pearson Higher Education, Inc., Upper Saddle River, NJ 07458. All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright and permissions should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use materials from this work, please submit a written request to Pearson Higher Education, Permissions Department, One Lake Street, Upper Saddle River, NJ 07458. Many of the designations by manufacturers and seller to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps. The author and publisher of this book have used their best efforts in preparing this book. These efforts include the development, research, and testing of theories and programs to determine their effectiveness. The author and publisher make no warranty of any kind, expressed or implied, with regard to these programs or the documentation | contained in this book. The author and publisher shall not be liable in any event for incidental or consequential 7 damages with, or arising out of, the furnishing, performance, or use of these programs. | About the cover photo | | The Tower of Pisa began to tilt during its construction in the 12" century. By the time construction was completed in 1370, the tower was tilting approximately 2° to the south. The tilt of the tower gradually increased over the centuries until it reached 54° in 1990, by which time the top of the tower was approximately 4% meters out of plumb. The tower was closed to the public in 1990 for fear that it might collapse, and a major international effort was undertaken to restore it to a safe condition. The cover photo shows the technique used to stabilize the tower. It invoived carefully removing soil from under the foundation on the north side of the tower with the drilling equipment shown in the photo. This allowed the tower to settle back to the north and reduced the tilt by 4°, moving the top of the tower back to the north by % meter. The tower is now back to the position it was in during the 1830s and has not moved significantly since being stabilizedTh.e tower was reopened to the public in 2001 (Burland et al. 2003 and 2009). Library of Congress Cataloging-in-Publication Data Coduto, Donald P. Geotechnical engineering: principles and practices / Donald P. Coduto, Man-chu Ronald Yeung, William A. Kitch. -- 2nd ed. p.cm. Includes bibliographical references and index. ISBN 0-13-236868-4 1. Engineering geology. I. Yeung, Man-chu Ronald, IL Kitch, William A. III. Title. TA705.C62 2011 624.1'51--de22 2010000164 Prentice Hall is an imprint of PEARSON 12 16 ISBN-13: 976-0-13-23b48b8-3 i ISBN-10: 0-13-23b4b4-4 : Contents Preface xX Acknowledgments xi About the Authors xii Notation & Units of Measurement Xili Chapter 1 Introduction to Geotechnical Engineering 1 1.1 Geotechnical Engineering Design Process 2 1.2 Historical Development 4 1.3 Modern Geotechnical Engineering 14 1.4 Accuracy of Geotechnical Engineering Analyses 16 1.5 A Pictorial Overview of Geotechnical Engineering 16 Chapter 2 Engineering Geology 28 2.1 The Geologic Cycle 29 Zk Rocks 30 2.3 Rock-Forming Minerals 35 2.4 Structural Geology 37 2.5 Weathering 43 2.6 ‘Soil Formation, Transport, and Deposition 45 2.7 Rock and Soil as Geomaterials 56 Summary 59 Questions and Practice Problems 61 Chapter 3 Site Exploration and Characterization 64 3.1 Project Assessment 65 3.2 Literature Search § 66 3.3 Remote Sensing 67 3.4 Field Reconnaissance and Surface Exploration 69 3.5 Subsurface Exploration 69 3.6 Soil and Rock Sampling 82 vi Contents 3.7 Groundwater Exploration and Monitoring 87 3.8 Ex Situ Testing 88 3.9 In Situ Testing 89 3.10 Geophysical Exploration 106 3.11 Synthesis and Interpretation 108 3.12 Economics 112 oad 3.13 Geotechnical Monitoring During Construction 113 Summary 113 Questions and Practice Problems 115 Chapter 4 Soil Composition 121 4.1 Soil as a Particulate Material 122 4.2 The Three Phases 122 43 Weight—Volume Relationships 124 4.4 Particle Size and Shape 138 4.5 Clay Soils 148 4.6 Plasticity and the Atterberg Limits Ist 4.7 Structured Versus Unstructured Soils 155 4.8 Organic Soils 156 Summary 157 Questions and Practice Problems 158 Chapter 5 Soil Classification - 164 5.1 USDA Soil Classification System 164 5.2 AASHTO Soil Classification System 167 5.3 Unified Soil Classification System (USCS) 171 5.4 Visual-Manual Soil Classification 180 5.5 Supplemental Soil Classifications 182 5.6 Applicability and Limitations 185 Summary 186 Questions and Practice Problems 187 Chapter 6 Excavation, Grading, and Compacted Fill 190 6.1 Earthwork Construction Objectives 192 6.2 Construction Methods and Equipment 193 6.3 Soil Compaction Concepts 213 66..54 FSoiiell d CoComnpsaicdteiroant ioSntsa ndanadr dsM onaindt orSipnegc ificati2o9n7 s 215 66..76 ESuairttabhiwloirtyk oQf uaSonitlis tyf or CoUmspe utaas tiCoonmsp acted2 37F ill 23|5 6.8 Lightweight Fills 241 6.9 Deep Fills 243 Summary 244 Questions and Practice Problems _ 245 Contents vii Chapter 7 Groundwater—Fundamentals and One-Dimensional Flow 251 7.1 Hydrology 252 7.2 Principles of Fluid Mechanics 255 73 One-Dimensional Flow Through Soil 268 7.4 Flow Through Anisotropic Soils 284 Summary 287 . 4 Questions and Practice Problems 288 Chapter8 Groundwater— Multidimensional Flow and Applications 295 8.1 Multidimensional Flow 295 8.2 Flow Net Solution for Two-Dimensional Flow 298 8.3 Numerical and Physical Modeling of Two-Dimensional Flow 316 8.4 Two- and Three-Dimensional Flow to Wells 320 8.5 Groundwater Control 329 8.6 Contaminant Control and Remediation 337 8.7 Soil Migration and Filtration 341 oH Summary 350 Questions and Practice Problems 352 Chapter 9 Stress 361 9.1 Simplifying Assumptions 362. O.2 Mechanics of Materials Review: 363 9.3 Mohr Circle Analyses 368 9.4 Sources of Stress in the Ground © 378 9.5 Geostatic Stresses 378 9.6 Induced Stresses 381 9.7 Superposition 392 9.8 Effective Stresses . 395 9.9 Effective Stress Under Steady State Flow 405 9.10 Stresses in Layered Strata 408 Summary 409 Questions and Practice Problems 410 Chapter 10 Compressibility and Settlement 419 10.1 Physical Processes 422 10.2 Changes in Vertical Effective Stress 423 10.3 Distortion Settlement 426 10.4 Consolidation Settlement— Physical Processes _ 427 10.5 Consolidation (Oedometer) Test 432 10.6 Consolidation Status in the Field 444 10.7 Compressibility of Sands and Gravels 446 10.8 Consolidation Settlement Predictions 448 10.9 Secondary Compression Settlement 461 10.10 Crusts 463 viil Contents 10.11 Settlement of Unsaturated Soils 463 10.12 Heave Due to Unloading 464 10.13 Accuracy of Settlement Predictions 464 Summary 465 Questions and Practice Problems 467 _ Chapter 11 Rate of Consolidation 478 | 11.1 Terzaghi’s Theory of Consolidation 478 | 11.2 Consolidation Settlement Versus Time Computations 489 © 11.3 The Coefficient of Consolidation, cy 499 | 11.4 Accuracy of Settlement Rate Predictions. 504 11.5 Consolidation Monitoring 506 11.6 Other Sources of Time Dependent Settlement 512 11.7 Methods of Accelerating Settlements 514 Summary 518 7 Questions and Practice Problems 520 Chapter 12 SoilStrength 527 12.1 Strength Analyses in Geotechnical Engineering 527 12.2 Shear Failure in Soils 529 12.3 The Drained and the Undrained Conditions 536 - 12.4 Mohr—Coulomb Failure Criterion . 539 12.5 Shear Strength of Saturated Sands and Gravels 545 12.6 Shear Strength of Saturated Clays 550 12.7 Shear Strength of Saturated Intermediate Soils 563 12.8 Shear Strength of Unsaturated Soils 564 12.9 Shear Strength Evaluation 564 12.10 Shear Strength at Interfaces Between Soil and Other Materials 583 12.11 Uncertainties in Shear Strength Assessments 584 Summary 585 Questions and Practice Problems 587 Chapter 13 Stability of Earth Slopes 593 13.1 Terminology 595 13.2 Modes of Slope Instability 597 13.3 Analysis of Slope Stability 604 13.4 Quantitative Analysis of Slides 605 13.5 General Procedures in a Limit Equilibrium 13.6 Planar Failure Analysis 608 q ‘oat oo 13.7 Infinite Slope Analysis 611 13.8 Swedish Slip Circle Method (6 = 0A 13.9 Method of Slices 618 nalysis) 18 13.10 Chart Solutions 627 13.11 Miscellaneous Issues 629 Contents ix 13.12 Seismic Stability 631 13.13 Stabilization Measures 636 13.14 Instrumentation 643 Summary 648 Questions and Practice Problems 649 Chapter 14 ~=Foundations 655 14.1 Shallow Foundations 656 14.2 Deep Foundations 658 Summary 671 Chapter 15 Spread Footing Design 673 15.1 Bearing Pressure 673 15.2 Bearing Capacity 675 15.3 Settlement 685 15.4 Spread Footings—Summary and Design Concerns 698 Summary 703 Questions and Practice Problems 704 Chapter 16 Earth Retaining Structures 709 16.1 Externally Stabilized Systems 709 16.2 Internally Stabilized Systems 714 16.3 Design of Earth Retaining Structures 717 Summary 719 Chapter 17 Lateral Earth Pressures 720 17.1 Lateral Earth Pressures and Wall Movement 720 17.2 Classical Lateral Earth Pressure Theories 726 17.3 Equivalent Fluid Pressure 742 17.4 Groundwater Effects 744 Summary 747 Questions and Practice Problems 748 Appendix A Finite Difference Solutions to Flow Problems 751 Appendix B Recommended Resources for Further Study (viewed online at www.pearsonhighered.com/Coduto) Appendix C Field Identification of Soils (viewed online at www.pearsonhighered.com/Coduto) References 765 Author Index = (viewed online at www.pearsonhighered.com/Coduto) Subject Index 779 Preface This second edition of Geotechnical Engineering: Principles and Practices reflects our experiences using the first edition with our own students over the past 12 years, as well as constructive suggestions we received from faculty, students, and practicing engineers, Some topics have been condensed or eliminated, while others have been expanded, clarified, or added. The primary target audience remains the same: undergraduate civil engineering students in their first geotechnical engineering course. WHAT IS NEW IN THIS EDITION This edition benefits from the addition of two new co-authors: Man-chu Ronald Yeung and William A. Kitch. The three of us are colleagues at Cal Poly Pomona. Each brings unique experiences and skills to the manuscript, and we believe the final product has benefitted from this collaboration. ; We have strengthened the coverage of “principles” to facilitate a better under- standing of fundamental geotechnical engineering concepts and to provide a firmer foundation for more advanced studies. These discussions include extensive narratives intended to impart an understanding of the underlying physical processes, not just an ability to do computations. The book also retains a “practices” component, which intro- duces students to the practical application of these principles to real engineering prob- lems. Although this book is not intended to be a comprehensive treatise on geotechnical engineering practice, we have found that a mix of theory and lication facilitates the most effective learning. y application ‘acts Every chapter has some updates, s ; noteworthy i. mprovements include the f9 olOlmoewi ngo:f W hich are quit. e extensiv° e. The m ost e The chapter on soil strength has be pees gy age of the underlying physical behavio snes to provide more in-depth cover e The chapter on slope stability has been enhanced ¢ The coverage of structural foundatio ns h | « A new appendix, Finite Difference ¢ as been expanded to two chapters. olutions to Flow Problems, has been added.