Mizunami Underground Research Laboratory Project (Rock mechanical investigations); In situ stress measurements and the laboratory tests using core on GL.-100m level of research gallery

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

JAEA-Research 2010-002, 48 Pages, 2010/06

JAEA-Research-2010-002.pdf:5.92MB

Japan Atomic Energy Agency is advancing the geo-scientific research at the Mizunami Underground Research Laboratory. In Phase II of the research, improvement on the previous conceptual model of the geological environment is one of the objectives. So the additional rock mechanical investigations on the GL.-100m level research gallery was conducted. As a result, the average rock physical and mechanical properties are consistent with the results from MIZ-1 testing. This means that the surface based investigations in MIZ-1 are valid at this level. Almost all in situ stress measurements indicate that the maximum principal stress is oriented in the NW-SE direction and match the observations in MIZ-1 at GL.-200m depth. But the observed stress level is not the expected value extrapolated from the MIZ-1 results. This suggests that the in situ stress has likely been decoupled at the rock boundary located about GL.-150m level between the Toki Lignite-bearing formation and the Toki granite.

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2006

Nishio, Kazuhisa; Matsuoka, Toshiyuki; Mikake, Shinichiro; Tsuruta, Tadahiko; Amano, Kenji; Oyama, Takuya; Takeuchi, Ryuji; Saegusa, Hiromitsu; Hama, Katsuhiro; Yoshida, Haruo*; et al.

JAEA-Review 2009-001, 110 Pages, 2009/03

JAEA-Review-2009-001.pdf:49.84MB

Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is developing a geoscientific research project named Mizunami Underground Research Laboratory (MIU) project in crystalline rock environment in order to establish scientific and technological basis for geological disposal of HLW. Geoscientific research at MIU is planned to be carried out in three phases over a period of 20 years; Surface-based Investigation Phase (Phase 1), Construction Phase (Phase 2) and Operation Phase (Phase 3). Currently, the project is under the Construction Phase. This document presents the following results of the research and development performed in 2006 fiscal year, as a part of the Construction Phase based on the MIU Master Plan updated in 2002, (1) Investigation at the MIU Construction Site, (2) Construction at the MIU Construction Site, (3) Research Collaboration.

Theoretical study on crystalline rock for estimating long-term behavior (Contract research)

Ichikawa, Yasuaki*; Seno, Yasuhiro*; Hirano, Toru; Nakama, Shigeo; Matsui, Hiroya

JAEA-Research 2008-090, 52 Pages, 2008/11

JAEA-Research-2008-090.pdf:13.05MB

This report describes the results of the works in the fiscal year 2007. In Chapter 1, we described the overview and background of this study. In Chapter 2 a reaction theory of pressure dissolution of quartz was proposed and by using a homogenization analysis the dissolution of quartz in bentonite was simulated by a modified diffusion model. In Chapter 3 CLSM was used to acquire clearly focused three-dimensional images of granite specimens of Mizunami underground lab for stress relaxation tests, and observed the change of micro-scale structure including the mineral configuration under applying compression stress. The local strain distributions suggest that a shearing mode is dominant in the granite samples. In Chapter 4 a strong discontinuity concept is introduced in the micro-scale problem of the multi-scale homogenization analysis, and Toki granite sample problems were solved.

Phenomenological study on crystalline rock for evaluating of long-term behavior (Contract research)

Okubo, Seisuke*; Seno, Yasuhiro*; Hirano, Toru; Nakama, Shigeo; Matsui, Hiroya

JAEA-Research 2008-065, 51 Pages, 2008/08

JAEA-Research-2008-065.pdf:2.9MB

This report describes the results of the works in the fiscal year 2007. In Chapter 1, we described the overview and background of this study. In Chapter 2, the result of continuing creep test of Tage tuff which was started from the fiscal year 1997 was described. Although there was some annual variability, the precious data were obtained. In Chapter 3, the control program for the generalized relaxation test was developed. The generalized relaxation test of Toki granite was conducted in order to get basically data. In Chapter 4, the extended constitutive equation of variable compliance was analytically discussed. Using the data obtained in Chapter 3, the parameters of Toki granite of the constitutive equation were obtained and numerical simulation was conducted.

Phenomelogical study on crystalline rock for evaluating of long-term behavior (Contract research)

Okubo, Seisuke*; Seno, Yasuhiro; Nakama, Shigeo; Sato, Toshinori*; Hirano, Toru

JAEA-Research 2007-088, 118 Pages, 2008/03

JAEA-Research-2007-088.pdf:27.7MB

This report describes the results of the works in the FY2005 and 2006. In Chapter 2, as the fundamental study on time-dependent behavior, followings were described; (1) The result of continuing creep test of Tage tuff which was started from the FY1997. (2) The results of multi-stage creep test of Inada granite at mid-range temperature. (3) The consideration of the generalized relaxation test. (4) The consideration of new testing method to determine the parameter in the constitutive equation supposed by Okubo. In Chapter 3, followings were described; (1) The results of rock mechanical tests of Toki granite. (2) The results of obtained parameters for the constitutive equation considering time-dependent behavior by mechanical tests and numerical simulations. Furthermore, in this report, following two related studies were attached in appendix; (1) Study on evaluating the effects of scatter in in-situ rock properties. (2) Study on new rock classification method considering long-term behavior of rock mass.

Excavation disturbance analysis based on MBC Model for predicting of the rock mass behavior during excavation of shafts and research galleries at the Mizunami Underground Research Laboratory

Seno, Yasuhiro; Nakama, Shigeo; Sato, Toshinori*; Mori, Takayuki*; Morikawa, Seiji*; Tabei, Kazuto*; Suyama, Yasuhiro*; Murakami, Koji*

JAEA-Research 2007-080, 112 Pages, 2008/01

JAEA-Research-2007-080.pdf:8.37MB

A 3D MBC(Micro-mechanics Based Continuum model) numerical analysis was carried out to predict the rock mass behavior of the complex (articulated) section at -500 m. Properties were chosen based on the Rock Mechanics Model constructed in the Surface-based Investigation Phase (Phase I).

Final report on the surface-based investigation (phase I) at the Mizunami Underground Laboratory project

Saegusa, Hiromitsu; Seno, Yasuhiro; Nakama, Shigeo; Tsuruta, Tadahiko; Iwatsuki, Teruki; Amano, Kenji; Takeuchi, Ryuji; Matsuoka, Toshiyuki; Onoe, Hironori; Mizuno, Takashi; et al.

JAEA-Research 2007-043, 337 Pages, 2007/03

JAEA-Research-2007-043.pdf:28.14MB

The Mizunami Underground Laboratory (MIU) Project is a comprehensive research project investigating the deep underground environment within crystalline rock being conducted by Japan Atomic Energy Agency at Mizunami City in Gifu Prefecture, central Japan. This report summarizes the results of the Surface-based Investigation Phase, identifies future issues and provides direction for research to be conducted during Construction Phase and Operation Phase. The results compiled in this report will be utilized for the technical knowledge base on geological disposal of HLW, and can be used to enhance the technical basis for waste disposal in general and for development of government regulations.

Japanese underground research laboratory project and prediction of rock mass behavior around deep shafts and galleries using continuous and discontinuous models

Sato, Toshinori; Mikake, Shinichiro; Nakama, Shigeo; Seno, Yasuhiro; Mori, Takayuki*; Iwano, Keita*; Goke, Mitsuo*; Tada, Hiroyuki*

Proceedings of 7th International Conference on Analysis of Discontinuous Deformations (ICADD-7) (CD-ROM), p.245 - 256, 2005/12

Two one-thousand meter deep shafts and research galleries at several levels will be excavated in granite for the Mizunami Underground Research Laboratory (MIU) project. Research on the deep geological environment in this project will provide the basis for Research and Development on geological disposal of high-level radioactive waste. The site of MIU project is located in Mizunami, Gifu, in the central part of the main island of Japan. By July 2003, entrances to the shafts were constructed, and excavation of lower part of shaft entrance was started in March 2004. Current status (September 2005) of construction is excavation of the shafts to a depth of 150 m has been done. Mechanical investigations including hydraulic fracturing test and laboratory tests on core samples were performed, and numerical analysis using continuous model and discontinuous model; MBC (Micro-mechanics based continuum model), Crack tensor model and FRACOD (fracture propagation code), were also performed to predict mechanical stability of openings and support systems, and rock mass behavior around openings. In this analysis EDZ (Excavation Damaged Zone) due to blasting and excavation step were considered in same cases. This paper describes the current status of Mizunami Underground Research Laboratory for crystalline rock and the results of prediction for rock mass behavior around the deep underground openings using some analytical methods. Measurements during shaft sinking and future plan of investigations in the URL are also describes in this paper.

None

Miura, Makoto; Tsunoda, Naomi; Sato, Seiichi*; ; Igarashi, Miyuki; Seno, Shigeo

PNC TN841 77-25, 77 Pages, 1977/06

PNC-TN841-77-25.pdf:12.56MB

no abstracts in English

None

Tsunoda, Naomi; Miura, Makoto; ; Mano, Tadashi*; Seno, Shigeo; ;

PNC TN841 76-25, 182 Pages, 1976/07

PNC-TN841-76-25.pdf:13.64MB

no abstracts in English