Your guide to the design and construction of foundations on expansive soils Foundation Engineering for Expansive Soils fills a significant gap in the current literature by presenting coverage of the design and construction of foundations for expansive soils. Written by an expert author team with nearly 70 years of combined industry experience, this important new work is the only modern guide to the subject, describing proven methods for identifying and analyzing expansive soils and developing foundation designs appropriate for specific locations. Expansive soils are found worldwide and are the leading cause of damage to structural roads. The primary problem that arises with regard to expansive soils is that deformations are significantly greater than in non-expansive soils and the size and direction of the deformations are difficult to predict. Now, Foundation Engineering for Expansive Soils gives engineers and contractors coverage of this subject from a design perspective, rather than a theoretical one. Plus, they'll have access to case studies covering the design and construction of foundations on expansive salts from both commercial and residential projects. Provides a succinct introduction to the basics of expansive soils and their threats Includes information on both shallow and deep foundation design Profiles soil remediation techniques, backed-up with numerous case studies Covers the most commonly used laboratory tests and site investigation techniques used for establishing the physical properties of expansive soils If you're a practicing civil engineer, geotechnical engineer or contractor, geologist, structural engineer, or an upper-level undergraduate or graduate student of one of these disciplines, Foundation Engineering for Expansive Soils is a must-have addition to your library of resources.

Table of Contents:
Preface xv List of Symbols xix List of Abbreviations xxv 1. INTRODUCTION 1 1.1 Purpose 2 1.2 Organization 2 1.3 Terminology 4 References 7 2. NATURE OF EXPANSIVE SOILS 9 2.1 Microscale Aspects of Expansive Soil Behavior 9 2.1.1 The Clay Particle 10 2.1.2 Adsorbed Cations and Cation Hydration 15 2.1.3 The Clay Micelle 17 2.1.4 Crystalline and Osmotic Expansion 19 2.1.5 Effect of Mineralogy on Plasticity of Soil 21 2.1.6 Effect of Mineralogy on Expansion Potential 22 2.1.7 Effect of Type of Cation on Expansion Potential 22 2.2 Macroscale Aspects of Expansive Soil Behavior 24 2.2.1 Development of Natural Soil Deposits 24 2.2.2 Effect of Plasticity on Expansion Potential 26 2.2.3 Effect of Soil Structure, Water Content, and Density on Expansion Potential 27 2.3 Identification of Expansive Soils 30 2.3.1 Methods Based on Physical Properties 30 2.3.2 Mineralogical Methods 36 2.3.3 Chemical Methods 37 2.3.4 Comments on Identification Methods 39 2.4 Characteristics of Expansive Soil Profiles 40 2.4.1 Geographic Distribution of Expansive Soils 40 2.4.2 Expansive Soil Profiles 40 References 53 3. SITE INVESTIGATION 59 3.1 Program of Exploration 59 3.1.1 Reconnaissance Investigation 60 3.1.2 Preliminary Investigation 60 3.1.3 Design-Level Investigation 61 3.2 Forensic Investigation 68 References 72 4. SOIL SUCTION 74 4.1 Soil Suction Components 74 4.1.1 Matric Suction 76 4.1.2 Osmotic Suction 80 4.1.3 Total Suction 82 4.2 Soil Water Characteristic Curve 82 4.2.1 Mathematical Expressions for SWCC 84 4.2.2 Soil Water Characteristic Curves for Expansive Soils 86 4.2.3 Influence of Stress State on Soil Water Characteristic Relationships 89 4.2.4 Effect of Suction on Groundwater Profiles 89 4.3 Measurement of Matric Suction 90 4.3.1 Tensiometers 92 4.3.2 Axis Translation Technique 94 4.3.3 Filter Paper Method for Matric Suction 98 4.3.4 Thermal Conductivity Sensors 103 4.3.5 Electrical Resistance Sensors 104 4.4 Measurement of Osmotic Suction 105 4.4.1 Osmotic Tensiometers 105 4.4.2 Pore Fluid Extraction Technique 106 4.5 Measurement of Total Suction 107 4.5.1 Psychrometers 109 4.5.2 Filter Paper Method for Total Suction 110 References 114 5. STATE OF STRESS AND CONSTITUTIVE RELATIONSHIPS 119 5.1 State of Stress and Stress State Variables 119 5.2 Stress–Volume Relationships 124 5.3 Stress–Water Relationships 125 References 126 6. OEDOMETER TESTING 127 6.1 Consolidation-Swell and Constant Volume Tests 129 6.2 Correction of Oedometer Test Data 132 6.2.1 Correction for Oedometer Compressibility 133 6.2.2 Correction for Specimen Disturbance in the CV Test 137 6.2.3 Effect of the Corrections on Expansion Properties 138 6.3 Relationship Between CS and CV Swelling Pressures (the m Method) 140 6.4 Factors Influencing Oedometer Test Results 144 6.4.1 Initial Stress State Conditions 145 6.4.2 Soil Fatigue 146 6.4.3 Initial Consolidation of Sample 146 6.4.4 Time and Method of Inundation 147 6.4.5 Storage of Samples 148 6.4.6 Competency of Laboratory Personnel 149 References 149 7. WATER MIGRATION IN EXPANSIVE SOILS 152 7.1 Water Flow in Unsaturated Soils 153 7.1.1 Darcy’s Law for Unsaturated Soils 153 7.1.2 Water Mass Balance Equation 154 7.1.3 Vertical Seepage in Unsaturated Soil 155 7.1.4 Flow through Fractured Rocks and Bedding Planes 158 7.2 Depth and Degree of Wetting 162 7.2.1 Depth of Wetting 162 7.2.2 Degree of Wetting 163 7.2.3 Perched Water Tables in Layered Strata 164 7.2.4 Wetting Profiles 165 7.3 Determination of Final Water Content Profiles for Design 167 7.3.1 Hand Calculation of Final Water Contents for Design 168 7.3.2 Computer Modeling of Water Migration 170 7.4 Challenges in Water Migration Modeling for Expansive Soils 177 References 178 8. COMPUTATION OF PREDICTED HEAVE 182 8.1 Oedometer Methods 183 8.1.1 The Heave Equation 184 8.1.2 Computation of Free-Field Heave 186 8.1.3 Computation of Heave under an Applied Load 195 8.1.4 Computation of Design Heave 195 8.1.5 Discussion of Earlier Oedometer Methods Proposed to Compute Heave 201 8.1.6 Comments on the Heave Index 204 8.2 Soil Suction Methods 204 8.2.1 McKeen (1992) 205 8.2.2 Department of the Army (1983) 211 8.2.3 Hamberg and Nelson (1984) 212 8.2.4 Lytton (1994) 213 8.3 Empirical Methods 214 8.4 Progression of Heave with Time 214 8.4.1 Hyperbolic Equation 214 8.4.2 Use of Water Migration Modeling to Analyze Rate of Heave 221 8.5 Free-Field Surface Movement for Shrink–Swell Soils 222 8.6 Discussion of Heave Prediction 223 References 224 9. GENERAL CONSIDERATIONS FOR FOUNDATION AND FLOOR DESIGN 227 9.1 Risk and Life Cycle Costs 230 9.1.1 Classification of Expansion Potential 230 9.1.2 Risk Factor 234 9.2 Foundation Alternatives 243 9.3 Factors Influencing Design of Structures on Expansive Soils 243 9.3.1 Tolerable Foundation Movement 243 9.3.2 Design Life 251 9.3.3 Design Active Zone and Degree of Wetting 252 9.3.4 Site Grading 252 9.4 Remedial Measures 253 References 255 10. SOIL TREATMENT AND MOISTURE CONTROL 258 10.1 Overexcavation and Replacement 259 10.2 Prewetting Method 264 10.3 Chemical Admixtures 267 10.3.1 Lime Treatment 267 10.3.2 Cement Treatment 273 10.3.3 Fly Ash Treatment 274 10.3.4 Chemical Injection 274 10.4 Moisture Control Alternatives 275 10.4.1 Moisture Barriers 276 10.4.2 Subsurface Drains 281 10.4.3 Surface Grading and Drainage 283 10.5 Summary of Soil Treatment Methods 289 References 290 11. DESIGN METHODS FOR SHALLOW FOUNDATIONS 295 11.1 Spread Footing Foundations 295 11.1.1 Computation of Footing Heave 297 11.1.2 Spread Footing Design Examples 299 11.2 Stiffened Slab Foundations 308 11.2.1 Edge Heave and Center Heave 308 11.2.2 Differential Heave 311 11.3 Remedial Measures for Shallow Foundations 314 11.3.1 Footing Foundations 314 11.3.2 Stiffened Slab-on-Grade 317 11.3.3 Other Methods 318 References 318 12. DESIGN METHODS FOR DEEP FOUNDATIONS 320 12.1 Pier and Grade Beam Foundation 320 12.1.1 Design Methods 324 12.1.2 Load-Bearing Capacity 334 12.2 Patented Piers 335 12.2.1 Helical Piles 335 12.2.2 Micropiles 337 12.2.3 Push Piers 340 12.3 Deep Foundation Design Examples 342 12.3.1 Rigid Pier Design Example 342 12.3.2 APEX Design Example 345 12.3.3 Helical Pile Design Example 348 12.4 Remedial Measures for Deep Foundations 348 12.4.1 Pier and Grade Beam Foundation 349 12.4.2 Underpinning 349 References 350 13. FLOORS AND EXTERIOR FLATWORK 351 13.1 Slabs-on-Grade 351 13.2 Stiffened Slabs 356 13.3 Structural Floors 357 13.4 Exterior Slabs and Flatwork 358 13.5 Remediation Techniques 359 13.5.1 Structural Floor Systems 361 13.5.2 Moisture Control 361 13.5.3 Chemical Injection 361 13.5.4 Isolation of the Slab 361 13.5.5 Exterior Slabs 362 References 362 14. LATERAL PRESSURE ON EARTH RETAINING STRUCTURES 363 14.1 Computation of Lateral Pressure from Expansive Soils 363 14.2 Testing for Measuring Lateral Swelling Pressure 365 14.3 Reduction of Lateral Swelling Pressure 366 14.4 Design for Lateral Earth Pressure 367 References 370 Index 373