Investigations of multiphysical processes in geomaterials have come to the forefront due to the continuing interests in the application of such theories for solving complex geoenvironmental problems. The topic of geologic disposal of heat-emitting nuclear fuel requires the consideration of the simultaneous influences of mechanical deformations, fluid flow, heat transfer and chemical alterations. Similar processes are encountered in the geologic sequestration of greenhouse gases in fluidized forms, the extraction of geothermal energy from both shallow and deep sources, the fluid pressure-induced influences of faults during slip at a fault or rock fracture, the mechanics of frozen soils, and geomechanical influences of glacial advances. The complete consideration of all possible multiphysical interactions in geomaterials is a daunting task and clearly an unrealistic expectation. For example, the study of thermo-hydro-mechanical effects in geologic media has to consider the mechanics of typical porous skeletons due to elastic, plastic and creep behavior, the fluid transport characteristics of the intact skeleton, and how these processes in turn can be influenced by the mechanical alterations of the porous skeleton and the heat transfer processes. In addition, chemical actions can alter the mechanical, fluid flow and thermal properties of the geological medium. The coupled multiphysical influences can be made more complicated by introducing considerations such as anisotropy, heterogeneity of the porous fabric and non-saturation of the porous medium. Clearly, the consideration of all these processes is formidable when the constitutive functionals and parameters have to be determined experimentally to make the results meaningful for geoscientific applications. The situation becomes even more complex because the interpretation of material data gathered for geoscientific applications can vary from the laboratory miniature specimen scale through the bench scale to the field scale. The prudent approach is to keep the multiphysical interactions to a bare minimum so that the processes that are critical to geoscientific applications can be emphasized. Such an approach requires a great deal of experience and patience. Although this volume largely focuses on geomaterial behavior, the range of applications of the theories of thermo-poroelastic behavior extends beyond the geosciences and can provide useful approaches to modeling problems in diverse areas, from biomechanics, notably the mechanics of bone materials and soft tissues, to industrial processes, involving drying of porous materials.