Unsaturated Soils (PDF)

An understanding of the mechanical properties of unsaturated soils
is crucial for geotechnical engineers worldwide, as well as to
those concerned with the interaction of structures with the ground.
This book deals principally with fine-grained clays and silts, or
soils containing coarser sand and gravel particles but with a
significant percentage of fines.

The study of unsaturated soil is a practical subject, linking
fundamental science to nature. Soils in general are inherently
variable and their behaviour is not easy to analyse or predict, and
unsaturated soils raise the complexity to a higher level. Even
amongst practicing engineers, there is often lack of awareness of
the intricacies of the subject. This book offers a perspective of
unsaturated soils based on recent research and demonstrates how
this dovetails with the general discipline of soil mechanics.

Following an introduction to the basic soil variables, the
phases, the phase interactions and the relevance of soil structure,
an up-to-date review of laboratory testing techniques is presented.
This includes suction measurement and control techniques in
triaxial cell testing. This is followed by an introduction to
stress state variables, critical state and theoretical models in
unsaturated soils.

A detailed description of the thermodynamic principles as
applied to multi-phase materials under equilibrium conditions
follows. These principles are then used to explore and develop a
fundamental theoretical basis for analysing unsaturated soils. Soil
structure is broken down into its component parts to develop
equations describing the dual stress regime. The critical state
strength and compression characteristics of unsaturated soils are
examined and it is shown how the behaviour may be viewed as a
three-dimensional model in dimensionless stress-volume space. The
analysis is then extended to the work input into unsaturated soils
and the development of conjugate stress, volumetric and
strain-increment variables. These are used to examine the
micromechanical behaviour of kaolin specimens subjected to triaxial
shear strength tests and lead to observations not detectable by
other means.

Unsaturated Soils: A fundamental interpretation of soil
behaviour covers a rapidly advancing area of study, research
and engineering practice and offers a deeper appreciation of the
key characteristics of unsaturated soil. It provides students and
researchers with a framework for understanding soil behaviour and
demonstrates how to interpret experimental strength and compression
data.

* provides engineers with a deeper appreciation of key
characteristics of unsaturated soils

* covers a rapidly advancing area of study, research and
engineering practice

* provides students and researchers a framework for understanding
soil behaviour

* shows how to interpret experimental data on strength and
compression

* the limited number of books on the subject are all out of
date