This book is, essentially, a textbook for a graduate-level course in slope stability analysis. It is a comprehensive reference to the physics of slope stability and groundwater flow, which will be of use primarily to researchers in landslide processes, geotechnical engineers, and developers and advanced users of numerical slope stability models. It is highly mathematical in approach (by my count, there are 367 equations!), and discusses both analytic and numeric solutions to the classic problems of infiltration, subsurface flow, total and effective stress and slope stability analysis.
The book begins with a brief review (chapters 1 and 2) of landslide classification and behaviour, soil classification, surface water hydrology and groundwater hydrology. Chapters 3 and 4 proceed to a detailed treatment of infiltration theory. This includes a useful review of some concepts from soil physics, including soil water characteristic curves, flow through layered media, and capillary barriers. In chapters 5 and 6, the classical theories of total and effective stress are discussed, including some detailed examples of finite-element solutions. Chapter 7 gives a brief review of the concepts of shear strength, including friction angle, cohesion, cementation and strength due to plant roots. Laboratory methods of measuring soil water characteristic curves and unsaturated hydraulic conductivity are described in chapter 8. In chapters 9 and 10, the classical approaches of infinite slope analysis and the method of slices are briefly reviewed, and several more advanced methods are developed. These include extension of the classical methods to unsaturated conditions, and numerical computation of the stress field and local factor of safety in two-dimensional slopes.
Several case studies are presented which are interesting applications of modern advances in numerical computation methods. These present the factor of safety as a continuously variable field for a cross-section through a potentially failing slope, rather than the usual simplification of a single factor of safety which applies to an entire assumed failure plane. These simulations allow one to visualize where in the slope failure might be initiated, under various infiltration scenarios representing rainstorms or snowmelt. The case studies and models of slope stability analysis emphasize pore water pressure in the unsaturated zone (suction stress). This is often neglected in simpler models, but can be important in cases where failure occurs under unsaturated conditions.
The approaches presented in this book are applicable mainly to engineered slopes for which the material properties are simple and well known, or to intensively studied chronic landslides for which detailed borehole information has been obtained. They are of limited applicability to most natural landslides in remote locations, for which detailed geotechnical information is lacking. In such cases, simpler classical methods of calculating or estimating slope stability are probably of greater practical value. In the natural world, the location and timing of landslides in surficial material are often influenced by local variability of soil properties, unknown structural discontinuities, complex layering and gradations in texture, macropores, tree roots, faults, deformation history, fingering flow during infiltration, and other random or unknown factors. The highly analytical approach does not, and probably cannot, consider most of these factors.
This book is an up-to-date, comprehensive reference that should be valuable for advanced geotechnical studies at well-instrumented sites. Those dealing with landslides in most natural settings such as forests (which is this reviewer’s background) will find it less practical.
British Columbia Forest Service (Ministry of Forests, Lands and Natural Resource Operations)
© 2014 Canadian Water Resources Association
http://dx.doi.org/10.1080/07011784.2014.985516