# Advanced Soil Mechanics

#### By **Braja M. Das**

CRC Press – 2008 – 600 pages

This revised and updated edition of Advanced Soil Mechanics presents a step-by-step guide to all aspects of the subject to students, and addresses a wide range of topics in a logical and extensively illustrated approach, including: grain-size distribution; the nature of water in clay; consistency of cohesive soils; weight-volume relationships; soil classification systems; concepts of elasticity; equations of equilibrium.

The book is illustrated with mathematical derivations and clear diagrams, problems and examples are provided throughout and each chapter concludes with a list of references for further in-depth review or research. Advanced Soil Mechanics is valuable not only for upper-level undergraduate and graduate level students of civil engineering, engineering mechanics, and soil mechanics, but also as a reference for professionals working in these fields.

CHAPTER 1 – SOIL AGGREGATE, PLASTICITY, AND CLASSIFICATION

1.1 Introduction

1.2 Soil-Separate Size Limits

1.3 Clay Minerals

1.4 Nature of Water in Clay

1.5 Repulsive Pressure

1.6 Flocculation and Dispersion of Clay Particles

1.7 Consistency of Cohesive Soils

1.8 Liquidity Index

1.9 Activity

1.10 Grain-Size Distribution of Soil

1.11 Weight-Volume Relationships

1.12 Relative Density and Relative Compaction

1.13 Effect of Roundness and Non-plastic Fines on e_{max} and e_{min} of Granular Soils

1.14 Unified Soil Classification System

References

This is an expanded chapter. The word "plasticity" has been added to the title. Sections 1.3, 1.5, 1.6, 1.7, 1.9, 1.10, 1.13, and 1.14 are new additions compared to the second edition. The Gouy-Chapman theory is given in Section 1.5. Langmuir’s equation is given in Section 1.6. Van der Wall’s forces are discussed in Section 1.7. The fall cone method is discussed in Section 1.8. Section 1.14 gives the effect of roundness (Youd, 1973) and non-plastic fines (Lade et al., 1998; Cubrinovski and Ishihara, 1999 and 2002) on maximum and minimum void ratios.

Number of figures – 38

Number of tables – 6

Number of example problems – 2

CHAPTER 2 – STRESSES AND STRAINS – ELASTIC EQUILIBRIUM

Introduction

Basic Definition and Sign Convention for Stresses

Equations for Static Equilibrium

Concept of Strain

Hooke’s Law

Plane Strain Problems

Equations of Compatibility for Three Dimensional Problems

Stresses on an Inclined Plane and Principal Stresses for Plane Strain Problems

Strains on an Inclined Plane and Principal Strains for Plane Strain Problems

Stress Components on Inclined Plane, Principal Stresses, and Octahedral Stresses – Three Dimensional Case

Strain Components on Inclined Plane, Principal Strains, and Octahedral Stresses – Three Dimensional Case

References

There are no changes from the second edition in this chapter.

Number of figures – 22

Number of tables – None

Number of sample problems – 5

CHAPTER 3 – STRESSES AND DISPLACEMENTS IN A SOIL MASS

3.1 Introduction

Two Dimensional Problems

Vertical Line Load on the Surface

Vertical Line Load on the Surface of a Finite Layer

Vertical Line Load inside a Semi-Infinite Mass

Horizontal Line Load on the Surface

Horizontal Line Load inside a Semi-Infinite Mass

Uniform Vertical Loading on an Infinite Strip on the Surface

Uniform Strip Load inside a Semi-Infinite Mass

Uniform Horizontal Loading on an Infinite Strip on the Surface

Triangular Normal Loading on an Infinite Strip on the Surface

Vertical Stress in a Semi-Infinite Mass Due to Embankment Loading

Three Dimensional Problems

tresses Due to Vertical Point Load on the Surface

Deflection Due to a Concentrated Point Load on the Surface

Horizontal Point Load on the Surface

Stresses Below a Circularly Loaded Flexible Area (Uniform Vertical Load)

Vertical Displacement Due to a Uniformly Loaded Circular Area on the Surface

Vertical Stress below a Rectangular Loaded Area on the Surface

Average Vertical Stress Increase Due To a Uniformly Loaded Rectangular Area

Deflection Due to a Uniformly Loaded Flexible Rectangular Area

Stresses in a Layered Medium

Vertical Stress at the Interface of a Three-Layer Flexible System

References

Changes from second edition:

The word "displacement" is added in title

Vertical displacement added in Section 3.2

Vertical stress and displacement given with tables (Poulos, 1966) in Section 3.3

Expanded table for vertical stress in Section 3.7; relationship for vertical displacement at surface added

Vertical displacement relationship added in Section 3.9

Equation in rectangular coordinate system added in Section 3.10; also vertical deflection relationship at the surface added

Section 3.13 new

Deflection relationship added in Section 3.14

Section 3.16 new

Tables and equations for determination of vertical stress below the center of a rectangular area added

Section 3.18 new (Griffiths, 1984, Canadian Geotechnical Journal)

__Section 3.19 new
__

Number of tables – 23

Number of figures – 33

Number of example problems – 7

CHAPTER 4 – PORE WATER PRESSURE DUE TO UNDRAINED LOADING

Introduction

Pore Water Pressure Developed Due to Isotropic Stress Application

Pore Water Pressure Parameter B

Pore Water Pressure Due to Uniaxial Loading

Directional Variation of A_{f
}

Pore Water Pressure under Triaxial Test Conditions

Henkel’s Modification of Pore Water Pressure Equation

Pore Water Pressure Due to One Dimensional Strain Loading (Oedometer Test)

References

Changes from second edition:

Section 4.3 is new. Discusses B with numerical values of the compressibility of pore water and soil skeleton (soft, medium, stiff, and very still soils).

__Section 4.5 is new. Discusses A _{f} with directional variation of major principal stress for clay soils (anisotropy).
__

Number of figures – 14

Number of tables – 4

Number of example problems – 1

CHAPTER 5 – PERMEABILITY AND SEEPAGE (tentative)

5.1 Introduction

Permeability

Darcy’s Law

Determination of hydraulic conductivity in the laboratory (constant head test, falling head test, from consolidation test, constant rate of strain test)

Permeameters for testing of clay soils

Kozeny-Carman equation

Estimation of hydraulic conductivity of granular soil using the Kozeny-Carman equation with examples (Carrier III, 2003, ASCE)

Estimation of k in cohesive soils with examples

Laboratory test for k in coarse sand and gravel (Kenney, Lau, and Ofoegbu, 1984, Canadian Geotechnical Journal)

Hydraulic conductivity in compacted soil (effect of confining pressure, molding moisture content)

Anisotropy with respect to hydraulic conductivity (additional experimental results)

Hydraulic conductivity in stratified soil – including laboratory experimental results (see Sridhavan and Prakash, 2002, ASTM Geotechnical Testing Journal)

In situ hydraulic conductivity for compacted clay

Seepage

uation of continuity

Use of continuity equation for solution of flow problems

Flow nets

Hydraulic uplift force under a structure

Flow nets in anisotropic material

Construction of flow nets for hydraulic structures on non-homogeneous subsoils

Numerical analysis of seepage

Seepage force per unit volume of soil mass

Safety of hydraulic structures against piping

Filter design

Calculation of seepage through an earth dam resting on an impervious base

Plotting of phreatic line for seepage through earth dams

Entrance, discharge, and transfer conditions of line of seepage through earth dams

Flow net construction for earth dams (a number of changes in this section)

References

Major changes or completely new material in bold.

Approximate number of figures – 70

Approximate number of tables – 7

Approximate example problems – 10

CHAPTER 6 – CONSOLIDATION

6.1 Introduction

Theory of one dimensional consolidation

Degree of consolidation under time-dependent loading

Numerical solution for one dimensional consolidation

Standard one dimensional consolidation test and interpretation

Effect of sample disturbance on the e vs. log s' curve

Compression index correlation (some new correlations to be added)

Correlations for preconsolidation pressure (based on laboratory tests, field vane, piezocone, dilatometer test; see Nagaraj et al., 1985, 1986, ASTM Geotechnical Testing Journal; see Chang, 1991, Canadian Geotechnical Journal)

Secondary consolidation and general comments on consolidation test

Calculation of one dimensional consolidation settlement

Coefficient of consolidation

Correlation of C_{v} with index properties such as activity, liquid limit, shrinkage limit

Comparison of C_{v} obtained from various methods with field observations

Constant rate-of-strain consolidation tests

Constant-gradient consolidation test

Sand drains

Solution for radial drainage due to time-dependent loading

Constant rate of strain consolidation with radial drainage

Numerical solution for radial drainage (sand drain)

General comments on sand drain problems

Field observations for settlement of clay with sand drains

Prefabricated vertical drains (PVD)

Design of PVDs

Problems

Major changes or completely new material in bold.

Approximate number of figures – 40

Approximate number of tables – 10

Approximate example problems – 12-15

CHAPTER 7 – SHEAR STRENGTH OF SOILS (tentative)

Introduction

Mohr-Coulomb failure criteria

Shearing strength of granular soils

Critical void ratio and its relationship to liquefaction

Curvature of the failure envelope

General comments on the friction angle of granular soils

Correlation for friction angle of granular soils based on field tests (SPT, CPT, PMT, DMT)

Shear strength of granular soils under plane strain condition

Shear strength of cohesive soils

Unconfined compression test

Modulus of elasticity and Poisson’s ratio from triaxial tests

Relation between A_{f} and swell and collapse of compacted clayey soils

Friction angles f and f_{ult
}

Effect of rate of strain on the undrained shear strength

Stress path

Hvorslev’s parameters

Relations between moisture content, effective stress, and strength for clay soils

Correlations for effective stress friction angle

Anisotropy in undrained shear strength

Sensitivity and thixotropic characteristics of clay

Creep (rate process theory)

Vane shear test

Relation of undrained shear strength (S_{u}) and effective overburden pressure (p')

Correlations of undrained shear strength with results from VST, SPT, CPT, CPTV, PMT, and DMT

Other theoretical considerations – yield surfaces in three dimensions

Experimental results to compare the yield functions

References

Major changes or new material in bold.

Approximate number of figures – 80

Approximate number of tables – 10

Approximate example problems – 10

CHAPTER 8 – SETTLEMENT OF FOUNDATIONS

Introduction

Elastic settlement

Modulus of Elasticity and Poisson’s Ratio

Contact Stress and Settlement Profile of Foundations

Settlement Based on the Theory of Elasticity

Generalized Average Elastic Settlement Equation

Improved Equation for Elastic Settlement

Calculation of Elastic Settlement in Granular Soil Using Simplified Strain Influence Factor

Elastic Settlement of Sandy Soils – Burland and Burbidge’s Method

Consolidation Settlement

One Dimensional Primary Consolidation Settlement

Skempton-Bjerrum Modification for Consolidation Settlement Calculation

Settlement of Overconsolidated Clays

Settlement Calculation Using Stress Path

Comparison of Primary Consolidation Settlement Calculation Procedures

Secondary Consolidation Settlement

Precompression for Improving Foundation Settlement

References

Changes from the second edition:

Section 8.3 is new to this chapter

Section 8.4 is new to this chapter (Steinbrenner, 1934; Fox, 1948)

Section 8.6 is new (Mayne and Poulos, 1999)

Section 8.8 is new to this chapter

__New graphs and table in Section 8.14
__

Number of figures – 33

Number of tables – 9

Number of example problems – 9

APPENDIX A – CALCULATION OF STRESS AT THE INTERFACE OF A THREE-LAYERED FLEXIBLE SYSTEM

Comments: This is the table given on pages 96–123 of the second edition.

**Braja M. Das **was formerly Dean of the College of Engineering and Computer Science, California State University, Sacramento.

Name: Advanced Soil Mechanics (Hardback) – CRC Press

Description: By Braja M. Das. This revised and updated edition of Advanced Soil Mechanics presents a step-by-step guide to all aspects of the subject to students, and addresses a wide range of topics in a logical and extensively illustrated approach, including: grain-size...

Categories: Soil Mechanics