Investigation on time-dependent behavior of sedimentary rock (Phase 3)

Yamamoto, Takuya*; Aoki, Tomoyuki*; Jo, Mayumi*

For the rational design of the underground facility and for the safety during construction and operation it is necessary to consider the long-term stability of the rock mass around a drift. Especially, the time-dependent behavior of sedimentary rock is important because the mechanism of time-dipenednt is not well understood. Here, laboratory tests of rock specimens collected from the borehole investigation and numerical analysis on the stability of the rock mass around a drift were discussed for last two years. In this year, additional laboratory tests were performed to confirm the several important knowledges for last two years. Moreover, the preliminary numerical analysis was carried out to predict the EDZ due to excavation of underground facility.