Soil aggregate, plasticity, and classification
The fourth edition further examines the relationships between the maximum and minimum void ratios of granular soils and adds the American Association of State Highway and Transportation Officials (AASHTO) soil classification system. It summarizes soil compaction procedures and Proctor compaction tests. It introduces new sections on vertical stress due to a line load of finite length, vertical stress in Westergaard material due to point load, line load of finite length, circularly loaded area, and rectangularly loaded area.
The fourth edition further examines the relationships between the maximum and minimum void ratios of granular soils and adds the American Association of State Highway and Transportation Officials (AASHTO) soil classification system. It summarizes soil compaction procedures and Proctor compaction tests. It introduces new sections on vertical stress due to a line load of finite length, vertical stress in Westergaard material due to point load, line load of finite length, circularly loaded area, and rectangularly loaded area. The text discusses the fundamental concepts of compaction of clay soil for the construction of clay liners in waste disposal sites as they relate to permeability and adds new empirical correlations for overconsolidation ratio and compression index for clay soils. It provides additional information on the components affecting friction angle of granular soils, drained failure envelopes, and secant residual friction angles of clay and clay shale.
Contains 11 chapters
Provides new example problems
Includes SI units throughout the text
Uses a methodical approach
The author adds new correlations between field vane shear strength, preconsolidation pressure, and overconsolidation ratio of clay soils. He also revises and expands information on elastic settlement of shallow foundations, adds a precompression with sand grains, and presents the parameters required for the calculation of stress at the interface of a three-layered flexible system.
An ideal resource for beginning graduate students, the fourth edition of Advanced Soil Mechanics further develops the basic concepts taught in undergraduate study by presenting a solid foundation of the fundamentals of soil mechanics.
This book is suitable for students taking an introductory graduate course, and it can also be used as a reference for practicing professionals.
Soil aggregate, plasticity, and classification
Professor Braja Das served as dean of the college of engineering and computer science at California State University Sacramento, and is the author of several geotechnical engineering texts and reference books.
INDEX
Soil aggregate, plasticity, and classification
Introduction
Soil: Separate size limits
Clay minerals
Nature of water in clay
Repulsive potential
Repulsive pressure
Flocculation and dispersion of clay particles
Consistency of cohesive soils
Liquidity index
Activity
Grain-size distribution of soil
Weight–volume relationships
Relative density and relative compaction
Relationship between emax and emin
Soil classification systems
Compaction
Empirical relationships for proctor compaction tests
References
Stresses and strains: Elastic equilibrium
Introduction
Basic definition and sign conventions for stresses
Equations of 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 strain for plane strain problems
Stress components on an inclined plane, principal stress, and octahedral stresses: Three-dimensional case
Strain components on an inclined plane, principal strain, and octahedral strain: Three-dimensional case
Stresses and displacements in a soil mass: Two-dimensional problems
Introduction
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
References
Stresses and displacements in a soil mass: Three-dimensional problems
Introduction
Stresses due to a vertical point load on the surface
Deflection due to a concentrated point load at the surface
Horizontal point load on the surface
Vertical stress due to a line load of finite length
Stresses below a circularly loaded flexible area (uniform vertical load)
Vertical displacement due to uniformly loaded circular area at the surface
Vertical stress below a rectangular loaded area on the surface
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
Vertical stress in Westergaard material due to a vertical point load
Solutions for vertical stress in Westergaard material
Distribution of contact stress over footings
Reliability of stress calculation using the theory of elasticity
References
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 Af
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
Permeability
Introduction
Darcy’s law
Validity of Darcy’s law
Determination of coefficient of permeability in the laboratory
Variation of coefficient of permeability for granular soils
Variation of coefficient of permeability for cohesive soils
Directional variation of permeability in anisotropic medium
Effective coefficient of permeability for stratified soils
Determination of coefficient of permeability in the field
Factors affecting the coefficient of permeability
Electroosmosis
Seepage
Introduction
Equation of continuity
Use of continuity equation for solution of simple flow problem
Flow nets
Hydraulic uplift force under a structure
Flow nets in anisotropic material
Construction of flow nets for hydraulic structures on nonhomogeneous 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
References
Consolidation
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 versus log σ′ curve
Secondary consolidation
General comments on consolidation tests
Calculation of one-dimensional consolidation settlement
Coefficient of consolidation
One-dimensional consolidation with viscoelastic models
Constant rate-of-strain consolidation tests
Constant-gradient consolidation test
Sand drains
Numerical solution for radial drainage (sand drain)
General comments on sand drain problems
References
Shear strength of soils
Introduction
Mohr–Coulomb failure criterion
Shearing strength of granular soils
Critical void ratio
Curvature of the failure envelope
General comments on the friction angle of granular soils
Shear strength of granular soils under plane strain conditions
Shear strength of cohesive soils
Unconfined compression test
Modulus of elasticity and Poisson’s ratio from triaxial tests
Friction angles φ and φult
Effect of rate of strain on the undrained shear strength
Effect of temperature 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 clays
Vane shear test
Relation of undrained shear strength (Su) and effective overburden pressure (p′)
Creep in soils
Other theoretical considerations: Yield surfaces in three dimensions
Experimental results to compare the yield functions
References
Elastic settlement of shallow foundations
Introduction
Elastic settlement of foundations on saturated clay (Poisson’s ratio ν =0.5 )
Elastic settlement of foundations on granular soil
Settlement calculation of foundations on granular soil using methods based on observed settlement of structures and full-scale prototypes
Semi-empirical methods for settlement calculation of foundations on granular soil
Settlement derived from theory of elasticity
References
Consolidation settlement of shallow foundations
Introduction
One-dimensional primary consolidation settlement calculation
Skempton–Bjerrum modification for calculation of consolidation settlement
Settlement calculation using stress path
Comparison of primary consolidation settlement calculation procedures
Secondary consolidation settlement
Precompression for improving foundation soils
Precompression with sand drains
References
Appendix
Index