Rock mechanics stability analysis of the shafts and research galleries at the Mizunami Underground Research Laboratory; Japanese fiscal year, 2004 (Contract research)

Shibuya, Hitoshi*; Suzuki, Takashi*; Kuroda, Hidetaka

Initial design of shafts and tunnels of the Mizunami Underground Research Laboratory was done in FY2002, and preliminary analysis of those of 0 to 300 m depth was done in FY2003 on the basis of geological survey results obtained then. We have recently completed boring of MIZ-1 borehole and obtained geological data to the depth of 1,000 m. In order to confirm validity of the design, we have reviewed geological model, rock property, initial stress and other characteristics and conducted corrective analysis (two-dimensional) on the basis of the new data. In junction of shaft and sub-stage (horizontal tunnel) (100 m and 300 m depth) where stress might be concentrated, three-dimensional analysis was done.