3rd Edition
Soil Mechanics Concepts and Applications, Third Edition
Instead of fixating on formulae, Soil Mechanics: Concepts and Applications, Third Edition focuses on the fundamentals. This book describes the mechanical behaviour of soils as it relates to the practice of geotechnical engineering. It covers both principles and design, avoids complex mathematics whenever possible, and uses simple methods and ideas to build a framework to support and accommodate more complex problems and analysis.
The third edition includes new material on site investigation, stress-dilatancy, cyclic loading, non-linear soil behaviour, unsaturated soils, pile stabilization of slopes, soil/wall stiffness and shallow foundations.
Other key features of the Third Edition:
• Makes extensive reference to real case studies to illustrate the concepts described
• Focuses on modern soil mechanics principles, informed by relevant research
• Presents more than 60 worked examples
• Provides learning objectives, key points, and self-assessment and learning questions for each chapter
• Includes an accompanying solutions manual for lecturers
This book serves as a resource for undergraduates in civil engineering and as a reference for practising geotechnical engineers.
Origin and classification of soils
Introduction: what is soil mechanics?
Structure of the earth
Origin of soils
Soil mineralogy
Phase relationships for soils
Unit weight
Effective stress
Particle size distributions
Soil filters
Soil description
Index tests and classification of clay soils
Compaction
Houses built on clay
Key points
Self-assessment and Learning Questions
Origins and mineralogy of soils
Phase relationships, unit weight and calculation of effective stresses
Particle size analysis and soil filters
Index tests and classification
Compaction
Notes
References
Soil strength
Introduction
Stress analysis
Soil strength
Friction
Shearbox or direct shear apparatus
Presentation of shearbox test data in engineering units
Volume changes during shear
Critical states
Peak strengths and dilation
Shearbox tests on clays
Applications
Stress states in the shearbox test
Simple shear apparatus
Key points
Self-assessment and learning questions
Shearbox test
Development of a critical state model
Determination of peak strengths
Use of strength data to calculate friction pile load capacity
Stress analysis and interpretation of shearbox test data
References
Groundwater flow and control
Introduction
Pore water pressures in the ground
Darcy’s law and soil permeability
Laboratory measurement of permeability
Field measurement of permeability
Permeability of laminated soils
Mathematics of groundwater flow
Plane flow
Confined flownets
Calculation of pore water pressures using flownets
Quicksand
Unconfined flownets
Distance of influence
Soils with anisotropic permeability
Zones of different permeability
Boundary conditions for flow into drains
Application of well pumping formulae to construction dewatering
Numerical methods
Groundwater control
Unsaturated soils
Key points
Self-assessment and learning questions
Laboratory measurement of permeability; fluidisation; layered soils
Well pumping test for field measurement of permeability
Confined flownets and quicksand
Unconfined flownet
Flownets in anisotropic soils
Notes
References
One-dimensional compression and consolidation
Introduction and objectives
One-dimensional compression: the oedometer test
One-dimensional consolidation
Properties of isochrones
One-dimensional consolidation: solution using parabolic isochrones
Determining the consolidation coefficient cv from oedometer test data
Application of consolidation testing and theory to field problems
One-dimensional consolidation: exact solutions
Radial drainage
Limitations of the simple models for the behaviour of soils in one-dimensional compression and consolidation
Key points
Self-assessment and learning questions
Analysis and interpretation of one-dimensional compression test data
Analysis of data from the consolidation phase
Application of one-dimensional compression and consolidation theory to field problems
Notes
References
Triaxial test and soil behaviour
Introduction
Triaxial test
Stress parameters
Stress analysis of the triaxial test
Determining the effective angle of shearing resistance φ′ from triaxial shear tests
Undrained shear strengths of clay soils
Isotropic compression and swelling
Specimen preparation by one-dimensional compression and swelling: K consolidation
Conditions imposed in shear tests
Critical states
Yield
State paths during shear: normally consolidated and lightly overconsolidated clays
Peak strengths
Residual strength
Sensitive soils
Correlation of critical state parameters with index tests
Creep
Anisotropy
Unsaturated soils
Critical state model applied to sands
Non-linear soil models
Repeated or cyclic loading
Key points
Self-assessment and learning questions
Interpretation of triaxial test results
Determination of critical state and Cam clay parameters
Analysis and prediction of state paths using Cam clay concepts
Notes
References
Calculation of soil settlements using elasticity methods
Introduction
Selection of elastic parameters
Boussinesq’s solution
Newmark’s chart and estimation of vertical stress
Settlements due to surface loads and foundations
Influence factors for stress
Standard solutions for surface settlements on an isotropic, homogeneous, elastic half-space
Estimation of immediate settlements
Effect of heterogeneity
Cross-coupling of shear and volumetric effects due to anisotropy
Key points
Self-assessment and learning questions
Determining elastic parameters from laboratory test data
Calculation of increases in vertical effective stress below a surface surcharge
Calculation of increases in vertical effective stress and resulting soil settlements
Use of standard formulae in conjunction with one-dimensional consolidation theory
References
Plasticity and limit equilibrium methods for earth pressures and retaining walls
Engineering plasticity
Upper and lower bounds (safe and unsafe solutions)
Failure criteria for soils
Retaining walls
Calculation of limiting lateral earth pressures
Development of simple stress field solutions for a propped embedded cantilever retaining wall
Soil/wall friction
Mechanism-based kinematic and equilibrium solutions for gravity retaining walls
Reinforced soil walls
Compaction stresses behind backfilled walls
Key points
Self-assessment and learning questions
Calculation of lateral earth pressures and prop loads
Stress field limit equilibrium analysis of an embedded retaining wall
Mechanism-based limit equilibrium analysis of retaining walls
Reinforced soil retaining walls
Compaction stresses
References
Foundations and slopes
Introduction and objectives
Shallow strip foundations (footings): simple lower bound (safe) solutions
Simple upper bound (unsafe) solutions for shallow strip footings
Bearing capacity enhancement factors to account for foundation shape and depth, and soil weight
Shallow foundations subjected to horizontal and moment loads
Simple piled foundations: ultimate axial loads of single piles
. -crit or-peak
Pile groups and piled rafts
Lateral loads on piles
Introductory slope stability: the infinite slope
Analysis of a more general slope
Laterally loaded piles for slope stabilisation
Key points
Self-assessment and learning questions
Shallow foundations
Deep foundations
Laterally loaded piles
Slopes
References
In-ground retaining structures: embedded walls and tunnels
Introduction and objectives
Earth pressure coefficients taking account of shear stresses at the soil/wall interface
Limit equilibrium calculations for embedded retaining walls and ultimate limit state design
Calculation of bending moments and prop loads: serviceability limit states
Embedded walls retaining clay soils
Geostructural mechanism to estimate wall movements
Effect of relative soil: wall stiffness
Strip loads
Multi-propped embedded walls
Tunnels
Key points
Self-assesment and learning questions
Embedded retaining walls and ULS design
Tunnels
Note
References
Calculation of improved bearing capacity factors and earth pressure coefficients using plasticity methods
Introduction and objectives
Stress discontinuities and their use to calculate improved bearing capacity factors for a shallow foundation subjected to a vertical load: effective stress (φ′) analysis
Stress discontinuities and their use to calculate improved bearing capacity factors for a shallow foundation subjected to a vertical load: total stress (τu) analysis
Application to stress analysis
Shallow foundations subjected to inclined loads
Calculation of earth pressure coefficients for rough retaining walls
Sloping backfill
Wall with a sloping (battered) back
Improved upper bounds for shallow foundations
Key points
Self assesment and learning questions
Bearing capacity of foundations
Retaining walls and earth pressures
References
Site investigation, in situ testing and modelling
Introduction and objectives
Site investigation
In situ testing
Modelling
Ground improvement
Key points
Self-assessment and learning questions
In situ testing
Modelling
Ground improvement
Notes
References
Index
Biography
William Powrie FREng is Professor of Geotechnical Engineering and Dean of the Faculty of Engineering and the Environment at the University of Southampton, UK. He has extensive practical experience on projects and is Geotechnical Consultant to WJ Groundwater Ltd.
"… a very well thought out and useful publication."
—Building EngineerAbout the previous edition:
"One of, if not the best, currently available. It is quite unique and very well composed".
—W E Wilson, consulting engineer, Nashville Tennessee
