[S-MP44] メルト－延性－脆性岩体のダイナミクスとエネルギー・システム

[SMP44-P03] 脆性から延性挙動を示す条件下における岩石き裂の力学的・水理学的特性

*武山 詳¹、坂口 清敏¹、渡邉 則昭¹ (1.東北大学大学院環境科学研究科)

キーワード：脆性－延性遷移領域、EGS、力学特性、水理学特性

A new concept of Enhanced Geothermal System (EGS), in which geothermal fluids are produced from a fractured reservoir created artificially within an originally semi-brittle or ductile basement, has been proposed . To assess the potential of the new geothermal system, the “Japan Beyond-Brittle Project (JBBP)”has also been recently initiated, and the author have conducted fundamental investigations on mechanical and hydraulic characteristics of the new type of reservoir, in which the rock is first experiences hydraulically and/or thermally induced brittle failure, and then subjected to the temperature and pressure conditions where the rock exhibits semi-brittle or ductile stress-strain behavior at the natural condition. Kawarago tuff have been used in the present study, because brittle, semi-brittle and ductile stress-stain behaviors of the tuff specimen can be controlled only with confining stress level at the room temperature . At confining stresses up to 40 MPa, tri-axial compression and fluid flow experiments have been conducted on the specimens without and with thermal fracture.