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.

JOHN D. NELSON, has over 50 years of geotechnical
engineering experience with emphasis in expansive soils.??He is
Professor Emeritus of Civil Engineering at Colorado State
University, and Principal Engineer at Engineering Analytics,
Inc.

KUO CHIEH CHAO, has over 20 years of geotechnical
experience in foundation design and construction on expansive
soils. He is Vice President of Engineering Analytics, Inc. and
Adjunct Professor at Colorado State University.

DANIEL D. OVERTON, has over 30 years of geotechnical
engineering experience including foundation design for expansive
soils. He is President of Engineering Analytics, Inc. and a Faculty
Affiliate at Colorado State University.

ERIK J. NELSON, has over 30 years of experience in
geotechnical engineering, foundation design, and forensic
investigations for expansive soils. He is Vice President at
Engineering Analytics, Inc.

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.

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 StressVolume Relationships 124

5.3 StressWater 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<…