A Study on the meaning of geological investigation focusing on water inrush from viewpoint of geological risk

Otsu, Hiroyasu*; Okawa, Junnosuke*; Takeuchi, Ryuji  ; Saegusa, Hiromitsu; Ota, Yasutaka*

This study focused on the meaning of geological investigations on the geological risk, focusing on the risk caused by water inrush into underground structures such as tunnels/shafts constructed in discontinuous rock masses. In detail, water inrush evaluation using Discrete Fracture Network Model has been conducted focusing on what kind of geological investigation contributes to mitigation of losses due to geological risk. As a result, it is pointed out that it becomes possible to reduce a geological risk by accumulation of the further geological investigation although the risk increases temporarily by some geological investigation.