PREDICTION OF PERMEABILITY CHANGES IN ROCK MASS AROUND CAVERNS BY VIRTUAL FRACTURE MODEL

Abstract

In this study, we propose a method of analysis i. e. VIRTUAL FRACTURE MODEL to predict permeability changes caused by excavating a cavern in anisotropic fractured rock. In this method, based on permeability tensor calculated from in situ tests, fracture settings are virtually created with Bingham distribution. The alterations in permeability of the virtual fracture settings are predicted according to the anisotropic stress changes arround a cavern. This method was applied to predict the permeability changes in Super-Kamiokande excavated in Kamioka Mine at the depth of 1000m. Consequently, both in situ measurements and predictions showed an increase of permeability around caverns to be consistent with each other.