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Aoki, Kenji*; Mito, Yoshitada*; Minami, Masayuki*; Matsui, Hiroya; Niunoya, Sumio*
JAEA-Research 2007-077, 126 Pages, 2007/09
JAEA-Research-2007-077.pdf:16.68MB
To understand the size and state of EDZ is one of the problems in the technological development for geological disposal of HLW. AE which is measured directly and evaluate 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 measure AE in sedimentary soft rocks because of the difficulty to acknowledge a few AE waves with small energy. The author consulted AE properties of Horonobe siliceous rocks from laboratory tests and evaluated size and state of EDZ from numerical analysis.
Mito, Yoshitada*; Chang, C. S.*; Aoki, Kenji*; Matsui, Hiroya; Niunoya, Sumio; Minami, Masayuki*
Proceedings of 11th Congress of the International Society for Rock Mechanics (ISRM 2007), Vol.1, p.273 - 276, 2007/08
In order to examine the relationship between AE, stress change and rock failure, the authors conducted the high stiffness triaxial compression tests including AE measurements, and its simulations by DEM (Distinct Element Method) using the bonded particle model. As the result, it is clarified that predominant AE frequency is a significant AE parameters to monitor the stress change in fracturing process of soft sedimentary rocks. After that, the DEM simulation of the triaxial compression test using the bonded particles model is conducted to visualize the fracturing process in the rock specimen. As the results, the relationship between AE, stress change and rock failure is clarified. Furthermore the three-dimensional DEM simulation under the in-situ stress condition provides a successful result to examine the borehole breakout observed in the actual deep borehole in the soft sedimentary rock, and the applicability of the simulation to the actual field is verified.
Aoki, Kenji*; Mito, Yoshitada*; Kurokawa, Susumu*; Matsui, Hiroya; Niunoya, Sumio; Minami, Masayuki*
Dai-36-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koen Rombunshu, p.235 - 238, 2007/01
The monitoring of EDZ (Excavation Disturbed Zone) is one of the most important required technologies for the design of rock caverns such as the high-level radioactive waste repository. The authors developed the stress-based evaluation system of EDZ by AE monitoring and DEM (Distinct Element Method) simulation. In order to apply this system to the soft rock site, the authors try to grasp the relationship between AE parameters, stress change and rock failure by performing the high stiffness tri-axial compression tests including AE measurements on the soft rock samples, and its simulations by DEM using bonded particle model.
