Analysis of the characteristics of AE wave using boring core of sedimentary soft rock and study on the field measurement of AE for the evaluation of EDZ (Joint research)

To understand the size and state of EDZ accurately is one of the key issues in the technological development for geological disposal of High-Level Radioactive Waste. As one of these evaluation technologies, AE which is measured directly and evaluates EDZ is paid to attention inside and outside the country, and the utility is reported for the crystalline rock. However, there are few cases to apply AE in sedimentary soft rocks to EDZ evaluation because of the difficulty to measure a few AE waves with small energy. In this study, the authors made a series of laboratory tests including tri-axial test using the stiff and servo-controlled testing machine in order to clarify the possibility to measure AE waves in Neogene siliceous rocks in Horonobe, Hokkaido, Japan (2005). The authors conducted the high stiffness tri-axial compression tests with AE measurements. And, the authors extracted an effective AE parameter to the evaluation of EDZ in the neogene (2005). The authors evaluated the mechanism of EDZ, which assumed from the result in occurrence of crack in the rock by measurement system and DEM analysis, by using the effective parameter (2006). In the EDZ examination which is planned since the second stage, the authors constructed a concept of the necessary measurement and evaluation system (2007). (author)