2019 Volume 75 Issue 1 Pages 131-145
It is essential to examine the evolution in hydraulic properties of rocks near high level radioactive geological disposal facility for evaluating the performance of the disposal system under thermal-hydraulic-mechanical-chemical coupled conditions. Especially, geochemical reactions such as pressure solution within fractures should be understood for predicting long-term permeability change of the rock masses. In this study, we have developed a novel THMC coupled model that can consider the pressure solution occurring at contacting asperities within factures predicted by damage theory. Using the developed model, long-term prediction of rock permeability was conducted for fictitious porous rocks that are assumed to be purely composed of quartz. The predictions show that a number of fractures are generated near the disposal cavity and permeability increases in damaged zone during the excavation, and after excavation the permeability of the damaged zone decreases to that of intact zone due to pressure solution at contacting asperities within fractures.