Influence of excavation of disposal tunnel on the near-field coupled thermal, hydraulic and mechanical phenomena

処分坑道掘削のニアフィールド熱-水-応力連成現象への影響

千々松 正和*; 塚田 泰博*; 小林 晃*; 藤田 朝雄 

Chijimatsu, Masakazu*; Tsukada, Yasuhiro*; Kobayashi, Akira*; Fujita, Tomoo

In the international DECOVALEX-THMC project, the influence of coupled thermal, hydraulic and mechanical (THM) phenomena on the safety of the near-field of a typical hypothetical geological repository is studied. The hypothetical geological repository would be located in the Canadian Shield, with horizontal drift geometry, and the copper container for the Candu fuel emplaced in the drift would be surrounded by MX-80 bentonite. Properties of bentonite are calibrated against results from laboratory experiments by SKB and the CEA mock-up test. Furthermore, damage model of rock mass is used for the express the effect of excavation. By using calibrated bentonite model and damage model, influence of excavation tunnel is studied. As results, it is known that effect of property change of rock mass due to excavation is very low compared with property of bentonite itself.