This is the first comprehensive text book on poroelasticity. Those of the scientific community who deal with poroelastic problems in geoscience, have been long waiting for such a volume, and I do appreciate that Herb Wang did the job. Over the past two decades the author has made many valuable contributions in this field. Linear poroelasticity is a rheological concept for numerous geomechanical problems in fluid saturated rocks. Although the theory grossly simplifies the natural processes that take place in situ, it has been successfully applied to a remarkably wide spectrum of processes; e.g. in explaining fluctuations of water levels in wells induced by changes in barometric pressure, or tides, or variations in water loading of a lake; or for describing the behavior of soil samples in consolidation tests in a laboratory; in understanding land subsidence following fluid production from the subsurface; or the transient rising of well water levels when a pump extracts water from a different aquifer; and in approximating some of the physics behind reservoir induced seismicity, or water level changes that are associated with earthquakes. None of these phenomena can be explained by elasticity theory. Poroelasticity uses pore pressure or the increment of fluid content as an additional variable, and considers the conditions of drainage of pore fluid inside a medium. Like Darcy's law for fluid flow through a permeable medium, poroelasticty takes a macroscopic approach, meaning that the geometry of the pore space is not resolved. The most fundamental work on the theory has been contributed by K. Terzaghi and M.A. Biot. Wang's book starts with an introduction in which basic concepts, an overview of the history of poroelasticity and its analogy to thermoelasticity are presented. It is outlined that the theory has its roots in three disciplines: geomechanics, hydrogeology, and petroleum engineering. Chapter two is about the constitutive equations relating the components of stress or strain to pore pressure (or increment of fluid content). A significant role in poroelastic processes is played by the various rock parameters elaborated for porous media, five of which are independent. Many of them are presented in Chapter three; a frequently adopted full set of parameters includes the Poisson's ratios for both drained and undrained conditions, the shear modulus, Skempton's ratio (change of pore pressure per unit change of confining pressure under undrained condition) and hydraulic diffusivity. In Chapter four, the governing equations for fluid flow in a fully saturated, poroelastic medium are formulated in different ways. The author's words ‘The richness and variety of poroelastic phenomena arise from interactions between the mechanical requirements of force equilibrium and the fluid-flow requirement of continuity’ reflects correctly that coupling forms the core of the theory of poroelasticity. The remaining chapters deal with solutions for situations in which the theory can be applied in geomechanics and hydrogeology. Problems in unbounded domains are handled in Chapter five, for the full space and for the half space. The reader will also find time-dependent solutions based on Green's function for cases when fluid is instantaneously injected through a point(-like) source. Chapter six is about uniaxial strain problems that hold under field conditions when horizontal displacements are negligible. This assumption is e.g. made with pore pressure changes beneath a seabed, sediment loading and water level fluctuations in wells due to barometric loading. Plane strain and plane stress solutions for rectangular co-ordinates are presented in Chapter seven. Examples for plane strain problems are the mechanical loading of a drained half space, ground deformation due to fluid extraction from a line of wells and shear slip on faults. Pore pressure changes in a horizontal aquifer induced by the solid Earth tide are often interpreted assuming plane stress conditions. Sometimes, polar co-ordinates are more suitable to describe a specific phenomenon. Plane strain solutions for these cases are given in Chapter eight with discussions of sudden pressurization or stress relief of a long core; or of a borehole, where pressurization can ultimately lead to hydraulic fracturing. The important case of axial symmetry is considered in Chapter nine. Problems like vertical deformation due to pumping (including land subsidence due to fluid extraction from a circular reservoir), reverse well level fluctuations and laboratory pulse decay tests are outlined in some detail. Chapter ten summarizes a few fundamental aspects of numerical techniques for solving poroelastic problems, i.e. applying the finite-element method or the boundary-element method. Some general notes on integral transforms (Fourier, Laplace, Hankel) and useful relations among poroelastic parameters together with a list of parameter values for different types of rock are given in the appendix. Beginners in poroelasticity usually struggle with a large number of notations and symbols. This book is a remedy for such problems as it presents a complete formulation of the theory in homogeneous notation and its applications to geoscience. Similar material was so far only found in innumerable scientific articles, with strongly heterogeneous descriptions. The book also has a fine collection of literature on poroelasticity, including that of the late nineties. I learnt a lot when reading the book and did not find severe inconsistencies. A minor point is perhaps that tidal efficiency is considered as marine tidal loading close to the shoreline only. Various researchers take the pore pressure response of a confined aquifer to the solid Earth tide as this quantity. The latter phenomenon is hardly treated in the book although it is much more widely observed than loading in coastal areas, which superimposes the solid Earth tide effect. Also, I personally prefer the term rock parameter rather than rock constant, as used in Wang's book, acknowledging that constant rock parameter values are essential for the theory to be a linear one. Finally, at least for my taste, the cover of the book (not designed by the author) is by far too gloomy. Poroelasticity is fun, as is repeatedly expressed by Herb Wang. It would have deserved a more appealing outfit. Should bugs or mistakes will become known: The author announces he is trying to maintain a web page of errata, which is a good idea. Who should buy the book? Those who are dealing with poroelastic problems in one or another, may he or she come from a discipline in geoscience or from a field where similar concepts matter, like material sciences. It is an invaluable source for those who deal with poroelastic phenomena, physical parameters of porous rocks and its interrelations. Newcomers will find a much easier access to the world of poroelasticity than through formerly available sources. Still, they will need time to digest the wealth of material that is given. The book contains many more facts than are required to apply the theory to a particular problem. Thus, the volume may be seen as an analogue to the classical text book on heat conduction by Carslaw & Jaeger (late fifties) or that on rock mechanics by Jaeger & Cook (mid-seventies). Basic knowledge in mathematics and physics is a must. Students may therefore typically be at the master course level before they will find the book useful. For the scientist involved with poroelastic phenomena, the book is an excellent choice and can be strongly recommended.
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H-J. Kümpel (2002) studied this question.