Study of permeable structure distribution and hydrogeological structure model of granitic rocks; Features of the permeable structures deduced from the wall surface geological data of the Mizunami Underground Research Laboratory

Nohara, Tsuyoshi   ; Takeuchi, Ryuji  ; Sakai, Toshihiro

Focusing on the characteristics of the faults and fractures of the MIU, based on analysis of existing data and on geological investigations, we examined the geological and hydrological features of the deep underground granitic rocks in the site scale. As a result, main permeable structures of granitic rocks can be associated with the old structures formed with the faulting and/or hydrothermal activity in geological times. Furthermore, we examined the distribution of the major permeable structures, based on the distribution of the geological structures.