Studies on grouting performance for underground construction in crystalline rock

Matsui, Hiroya ; Tanaka, Tatsuya*; Fujii, Haruhiko*; Takeuchi, Shinji; Iyatomi, Yosuke ; Sugihara, Kozo

Grouting is practically important to reduce groundwater inflow into a cavern for construction of underground facilities. Studies on the grouting performance were carried out in Mizunami URL excavated in crystalline rock. The aims of these studies are to evaluate the applicability of existing grouting technology and to develop the methodology for the estimation of grouting performance, e.g., the extension of grout, hydraulic property change. The results suggests that the existing grouting technology is effective to reduce groundwater inflow into drifts and the hydraulic conductivity in the surrounding rock may decrease by two orders of magnitude before grouting.