Mizunami Underground Research Laboratory Project; Rock mechanical investigations in situ stress measurements using core-based methods on the -300 m stage

Sanada, Hiroyuki; Hikima, Ryoichi; Tanno, Takeo; Matsui, Hiroya ; Sato, Toshinori  ; Kato, Harumi*

The Mizunami Underground Research Laboratory Project has been implemented to establish the techniques for investigation, analysis and assessment of the deep geological environment and to develop a range of engineering techniques for application deep underground. In this paper, results of differential strain curve analysis (DSCA) and elastic wave measurements using polyhedral specimens at the 08MI13 and 09MI20 boreholes in -300 m stage are described. The objectives of this work are to evaluate in situ stress condition on the -300 m stage.