The definitive guide to the critical issue of slope stability and safety
Soil Strength and Slope Stability, Second Edition presents the latest thinking and techniques in the assessment of natural and man-made slopes, and the factors that cause them to survive or crumble. Using clear, concise language and practical examples, the book explains the practical aspects of geotechnical engineering as applied to slopes and embankments. The new second edition includes a thorough discussion on the use of analysis software, providing the background to understand what the software is doing, along with several methods of manual analysis that allow readers to verify software results. The book also includes a new case study about Hurricane Katrina failures at 17th Street and London Avenue Canal, plus additional case studies that frame the principles and techniques described.
Slope stability is a critical element of geotechnical engineering, involved in virtually every civil engineering project, especially highway development. Soil Strength and Slope Stability fills the gap in industry literature by providing practical information on the subject without including extraneous theory that may distract from the application. This balanced approach provides clear guidance for professionals in the field, while remaining comprehensive enough for use as a graduate-level text. Topics include:
Mechanics of soil and limit equilibrium procedures Analyzing slope stability, rapid drawdown, and partial consolidation Safety, reliability, and stability analyses Reinforced slopes, stabilization, and repair
The book also describes examples and causes of slope failure and stability conditions for analysis, and includes an appendix of slope stability charts. Given how vital slope stability is to public safety, a comprehensive resource for analysis and practical action is a valuable tool. Soil Strength and Slope Stability is the definitive guide to the subject, proving useful both in the classroom and in the field.
Foreword ix Preface xi Chapter 1 Introduction 1 Summary 3 Chapter 2 Examples and Causes Of Slope Failures 5 2.1 Introduction 5 2.2 Examples of Slope Failure 5 2.3 The Olmsted Landslide 11 2.4 Panama Canal Landslides 12 2.5 The Rio Mantaro Landslide 12 2.6 Kettleman Hills Landfill Failure 13 2.7 Causes of Slope Failure 13 2.8 Summary 17 Chapter 3 Soil Mechanics Principles 19 3.1 Introduction 19 3.2 Total and Effective Stresses 20 3.3 Drained and Undrained Shear Strengths 21 3.4 Basic Requirements for Slope Stability Analyses 26 Chapter 4 Stability Conditions for Analysis 31 4.1 Introduction 31 4.2 End-of-Construction Stability 31 4.3 Long-Term Stability 32 4.4 Rapid (Sudden) Drawdown 32 4.5 Earthquake 33 4.6 Partial Consolidation and Staged Construction 33 4.7 Other Loading Conditions 34 4.8 Analysis Cases for Earth and Rockfill Dams 34 Chapter 5 Shear Strength 37 5.1 Introduction 37 5.2 Behavior of Granular Materials—Sand, Gravel, and Rockfill 37 5.3 Silts 52 5.4 Clays 57 5.5 Municipal Solid Waste 78 Chapter 6 Mechanics of Limit Equilibrium Procedures 81 6.1 Definition of the Factor of Safety 81 6.2 Equilibrium Conditions 82 6.3 Single Free-Body Procedures 82 6.4 Procedures of Slices: General 87 6.5 Procedures of Slices: Circular Slip Surfaces 87 6.6 Procedures of Slices: Noncircular Slip Surfaces 94 6.7 Procedures of Slices: Assumptions, Equilibrium Equations, and Unknowns 105 6.8 Procedures of Slices: Representation of Interslice Forces (Side Forces) 105 6.9 Computations with Anisotropic Shear Strengths 112 6.10 Computations with Curved Strength Envelopes 112 6.11 Finite Element Analysis of Slopes 112 6.12 Alternative Definitions of the Factor of Safety 113 6.13 Pore Water Pressure Representation 116 Chapter 7 Methods of Analyzing Slope Stability 125 7.1 Simple Methods of Analysis 125 7.2 Slope Stability Charts 126 7.3 Spreadsheet Software 128 7.4 Finite Element Analyses of Slope Stability 129 7.5 Computer Programs for Limit Equilibrium Analyses 130 7.6 Verification of Results of Analyses 132 7.7 Examples for Verification of Stability Computations 134 Chapter 8 Reinforced Slopes and Embankments 159 8.1 Limit Equilibrium Analyses with Reinforcing Forces 159 8.2 Factors of Safety for Reinforcing Forces and Soil Strengths 159 8.3 Types of Reinforcement 160 8.4 Reinforcement Forces 161 8.5 Allowable Reinforcement Forces and Factors of Safety 162 8.6 Orientation of Reinforcement Forces 163 8.7 Reinforced Slopes on Firm Foundations 164 8.8 Embankments on Weak Foundations 164 Chapter 9 Analyses for Rapid Drawdown 169 9.1 Drawdown during and at the End of Construction 169 9.2 Drawdown for Long-Term Conditions 169 9.3 Partial Drainage 177 9.4 Shear-Induced Pore Pressure Changes 177 Chapter 10 Seismic Slope Stability 179 10.1 Analysis Procedures 179 10.2 Pseudostatic Screening Analyses 182 10.3 Determining Peak Accelerations 184 10.4 Shear Strength for Pseudostatic Analyses 184 10.5 Postearthquake Stability Analyses 188 Chapter 11 Analyses of Embankments with Partial Consolidation of Weak Foundations 193 11.1 Consolidation During Construction 193 11.2 Analyses of Stability with Partial Consolidation 194 11.3 Observed Behavior of an Embankment Constructed in Stages 195 11.4 Discussion 197 Chapter 12 Analyses to Back-Calculate Strengths 201 12.1 Back-Calculating Average Shear Strength 201 12.2 Back-Calculating Shear Strength Parameters Based on Slip Surface Geometry 203 12.3 Examples of Back-Analyses of Failed Slopes 205 12.4 Practical Problems and Limitation of Back-Analyses 213 12.5 Other Uncertainties 214 Chapter 13 Factors of Safety and Reliability 215 13.1 Definitions of Factor of Safety 215 13.2 Factor of Safety Criteria 216 13.3 Reliability and Probability of Failure 217 13.4 Standard Deviations and Coefficients of Variation 217 13.5 Estimating Reliability and Probability of Failure 220 Chapter 14 Important Details of Stability Analyses 227 14.1 Location of Critical Slip Surfaces 227 14.2 Examination of Noncritical Slip Surfaces 233 14.3 Tension in the Active Zone 234 14.4 Inappropriate Forces in the Passive Zone 238 14.5 Other Details 241 14.6 Verification of Calculations 245 14.7 Three-Dimensional Effects 246 Chapter 15 Presenting Results of Stability Evaluations 249 15.1 Site Characterization and Representation 249 15.2 Soil Property Evaluation 249 15.3 Pore Water Pressures 250 15.4 Special Features 250 15.5 Calculation Procedure 250 15.6 Analysis Summary Figure 250 15.7 Parametric Studies 254 15.8 Detailed Input Data 257 15.9 Table of Contents 257 Chapter 16 Slope Stabilization and Repair 259 16.1 Use of Back-Analysis 259 16.2 Factors Governing Selection of Method of Stabilization 259 16.3 Drainage 260 16.4 Excavations and Buttress Fills 263 16.5 Retaining Structures 264 16.6 Reinforcing Piles and Drilled Shafts 267 16.7 Injection Methods 269 16.8 Vegetation 269 16.9 Thermal Treatment 270 16.10 Bridging 270 16.11 Removal and Replacement of the Sliding Mass 271 Appendix A Slope Stability Charts 273 Appendix B Curved Shear Strength Envelopes Forfully Softened Shear Strengths and Their Impact on Slope Stability Analyses 289 References 295 Index 309
J. MICHAEL DUNCAN is University Distinguished Professor Emeritus of Civil and Environmental Engineering, and Co-Director of the Center for Geotechnical Practice and Research (CGPR) at Virginia Tech in Blacksburg, Virginia. STEPHEN G. WRIGHT is a professor emeritus of Geotechnical Engineering in the Department of Civil, Architectural, and Environmental Engineering at the University of Texas at Austin. THOMAS L. BRANDON is an associate professor of Civil and Environmental Engineering and Director of the W. C. English Geotechnical Research Laboratory at Virginia Tech in Blacksburg, Virginia.
