COUPLED HYDROMECHANICAL-THERMOCHEMICAL PROCESSES IN ROCK FRACTURES

The behavior of rock fractures under various coupled processes is reviewed under seven broad categories: (1) hydromechanical processes, (2) thermohydrologic processes, (3) hydrochemical processes, (4) thermohydromechanical processes, (5) thermohydrochemical processes, (6) hydromechanical-chemical processes, and (7) thermomechanical-hydrochemical processes. The state-of-the-art and possible directions of further research in these coupled processes are discussed. Rock fracture behaviors considered include not only dilation, closure, shear, and joint propagation but also changes in flow permeability and chemical sorption and retardation capabilities. These properties are of critical concern in practical considerations of the rock mass as a medium to store and isolate chemical and radioactive wastes. Investigations of coupled processes in two-fracture systems and multifracture systems are identified as important areas for future research. The need to consider coupled processes in borehole testing procedures involving rock fractures is emphasized.