Annual report on rock mechanics research at the Mizunami Underground Laboratory Project; FY2006

Seno, Yasuhiro*; Nakama, Shigeo ; Yamada, Atsuo*; Hirano, Toru; Sato, Toshinori*  

To establish a scientific and technical basis of geological disposal of high level radioactive waste, Japanese Atomic Energy Agency is advancing the geo-scientific research project of Mizunami Underground laboratory (MIU) in crystalline rock environment at Tono Geo-science Center. At MIU, the geo-scientific research is planned to be carried out in three Phases over a period of 20 years; Surface-based Investigation Phase, Construction Phase and Operation Phase. Currently, the Project is under the Construction Phase. This report presents the following results about rock mechanics studies conducted in the 2006 fiscal year, (1) The boring investigation for rock mechanics, from the connection gallery opened on G.L.-100m, (2) The advanced study for determination of three dimensional distributions of the initial rock stress, (3) The advanced study to evaluation of rock-stress using boring cores, (4) The basic study on crystalline rock for evaluation of long-term behavior.