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Kuboshima, Koji; Ishibashi, Masayuki; Sasao, Eiji; Tsuruta, Tadahiko; Tagami, Masahiko*; Yuguchi, Takashi
JAEA-Research 2012-037, 78 Pages, 2013/03
JAEA-Research-2012-037.pdf:235.85MB
The MIU (Mizunami Underground Research Laboratory) Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). Currently, the project is under Phase II and Phase III. One of Phase II goals is set up to develop and revise models of the geological environment using the investigation results obtained during excavation, and to determine and assess changes in the geological environment in response to excavation. This report aims compiling results of study on geology and geological structure from the surface to G.L. -300m in the Phase II and provides the fundamental information on the geology and geological structure for future study. The compiling results of this report reflected basic data are utilized in the updating of the geological models in the Phase II.
Tagami, Masahiko*; Yamada, Yasuhiro*; Yamashita, Yoshihiko*; Miyakawa, Ayumu*; Matsuoka, Toshifumi*; Xue, Z.*; Tsuji, Takeshi*; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Amano, Kenji; et al.
JAEA-Research 2012-036, 110 Pages, 2013/02
JAEA-Research-2012-036.pdf:44.93MB
Northeast strike faults developed in and around the Mizunami Underground Research Laboratory (MIU) control groundwater flow. These faults were possibly formed as a part of pull-apart structure by the right lateral movement of the Tsukiyoshi fault distributed in the north of MIU site. But the formational mechanism of these faults is still uncertain. In this joint research, the analog experiment and the numerical simulation were used to restore the geological structures around MIU site. The paleo-stress analysis were exposed an ancient deformation mechanism, and the formation timing was presumed in the regional tectonics. The results are adopted for the design of the analog experiment and the numerical simulation. The results of obtained analog experiment and numerical simulation are verified three-dimensionally, and then compared to the current geological structure model. Then the geological structure in the uninvestigated area is estimated.
Tsuruta, Tadahiko; Tagami, Masahiko; Amano, Kenji; Matsuoka, Toshiyuki; Kurihara, Arata; Yamada, Yasuhiro*; Koike, Katsuaki*
Chishitsugaku Zasshi, 119(2), p.59 - 74, 2013/02
Japan Atomic Energy Agency (JAEA) is developing a geoscientific research project, Mizunami Underground Research Laboratory (MIU) project, in order to establish scientific and technological basis for geological disposal of HLW. A series of geological mapping, reflection seismic survey, borehole investigation and geological investigations around research galleries are carried out to identify the distribution and the heterogeneity of fractures and faults that are potential major flow-pass of groundwater as field investigations. This paper describes geological investigations in the MIU project, focused on the evaluation of their effectiveness in order to understand the deep underground geological environment.
Yuguchi, Takashi; Tagami, Masahiko*; Tsuruta, Tadahiko; Nishiyama, Tadao*
Engineering Geology, 149-150, p.35 - 46, 2012/11
Times Cited Count：12 Percentile：44.45(Engineering, Geological)This paper describes the spatial distribution of fractures in the Toki granitic pluton, Central Japan and their evaluation with respect to the pluton's cooling behavior. Three-dimensional frequency distributions of entire fractures, based on borehole television data collected from 19 boreholes, shows that (1) the central region of the granite has a high fracture frequency and (2) fracture frequency decreases with decreasing elevation (datum is mean sea level), with the exception of the west side of the body. The development of sub-solidus reaction features was measured at two neighboring positions, and the difference was divided by the distance between the two positions. The resulting quantity is here defined as "local cooling rate". We observed a significant correlation between the distribution patterns of entire fracture frequency and local cooling rate; the region with a high local cooling rate corresponds to the region with a high frequency of entire fractures, and vice versa. This correlation indicates that fracture genesis can be explained by "local cooling rate", combined with the concept of thermal stress. Thus, the three dimensional pattern of local cooling rate is a potential diagnostic tool for quantifying the distribution of fracture frequency.
Tsuruta, Tadahiko; Takeda, Masaki; Ueno, Takashi; Daimaru, Shuji; Tokuyasu, Shingo; Onoe, Hironori; Shingu, Shinya; Ishibashi, Masayuki; Takeuchi, Ryuji; Matsuoka, Toshiyuki; et al.
JAEA-Technology 2012-001, 134 Pages, 2012/03
JAEA-Technology-2012-001.pdf:41.2MBJAEA-Technology-2012-001(errata).pdf:0.44MBJAEA-Technology-2012-001-appendix(CD-ROM).pdf:6.37MB
Tono Geoscientific Research Unit of Japan Atomic Energy Agency (JAEA) is performing the Mizunami Underground Research Laboratory (MIU) project in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The borehole investigations (two boreholes; 10MI22 borehole and 10MI23 borehole) have been carried out to obtain information on geological, hydrological and hydrochemical characteristics in and around the Main-shaft fault. These investigations provided that features of fracture and alteration on rock mass in and around the Main-shaft fault. Hydrological and hydrochemical properties based on the geological features were also obtained.
Tagami, Masahiko; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Yamada, Yasuhiro*; Matsuoka, Toshifumi*; Yamashita, Yoshihiko*; Miyakawa, Ayumu*
JAEA-Review 2010-069, p.125 - 126, 2011/02
no abstracts in English
Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Tagami, Masahiko; Ishida, Hideaki; Hayano, Akira; Kurihara, Arata; Yuguchi, Takashi
JAEA-Research 2010-039, 131 Pages, 2011/01
JAEA-Research-2010-039.pdf:25.36MB
Tono Geoscientific Unit of Geological Isolation and Development Directoratte is performing Mizunami Underground Research Laboratory (MIU) Project, which is a broad scientific study of the deep geological environment as a basis of research and development for geological disposal of nuclear wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. The MIU Project has three overlapping 3 phases, with a total duration of 20 years. The project goals of the MIU Project from Phase I through to Phase III are: to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a range of engineering for deep underground application. Currently, the project is under the Phase II. This document presents the overview of results of the research and development on "geology" performed in fiscal year 2008, with regard to the Phase II goal.
Tagami, Masahiko; Ishida, Hideaki; Tsuruta, Tadahiko
Nihon Oyo Chishitsu Gakkai Heisei-21-Nendo Kenkyu Happyokai Koen Rombunshu, p.175 - 176, 2009/10
Fractures in crystalline rocks have exerted a big influence on the underground water stream. It is necessary to understand the fracture shape and distribution from the viewpoint of the material transfer and the safety construction in designing the geological disposal facilities of the high-level nuclear waste. In this report, we examined the fracture characteristics along the horizontal tunnel which was named -300m Access/Research gallery in Mizunami Underground Research Laboratory. Spring water that exceeded 1000 liters per minute was confirmed in the horizontal boring investigation along the tunnel before gallery excavation. We considered the fracture formation process and the function as the passage of water.
Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Tagami, Masahiko; Kurihara, Arata; Amano, Kenji; Yamada, Yasuhiro*; Koike, Katsuaki*
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no abstracts in English
Tsuruta, Tadahiko; Ochi, Minoru; Yuguchi, Takashi; Tagami, Masahiko; Kakamu, Kazuhiko; Yoshida, Hidekazu*; Nishimoto, Shoji*; Nishiyama, Tadao*; Nakamata, Kiminori*
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no abstracts in English
Ishibashi, Masayuki; Tagami, Masahiko; Matsuoka, Toshiyuki; Tsuruta, Tadahiko
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no abstracts in English
Yamada, Yasuhiro*; Yamashita, Yoshihiko*; Miyakawa, Ayumu*; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Tagami, Masahiko
no journal, ,
Tsukiyoshi fault displaces Toki granite and middle Miocene Mizunami group, and it was regarded as the reverse fault from apparent displacement. However, the arrangement of the Tsukiyoshi channel and several NNW-SSE trend faults between the right step region of ENE-WSW strike Tsukiyoshi Fault. This implies that right-lateral displacement created a pull-apart basin. In order to support this working hypothesis, we have designed analogue experiment and 3-D numerical simulation, to restore a similar structure around the southern side of Tsukiyoshi fault. It succeeded in reproducing similar structures of the present geological model in analogue experiment by dextral moving the reduced 3-D block model of the present Tsukiyoshi fault plane.
Matsuoka, Toshiyuki; Tsuruta, Tadahiko; Tagami, Masahiko; Ishibashi, Masayuki; Tokuyasu, Shingo; Ueno, Takashi; Yuguchi, Takashi
no journal, ,
Current status of geological investigations of the MIU Project Phase II are summarized. Geological mapping, reverse VSP, Analog model simulation and so on, were conducted as Phase II investigations. As results of these investigations, the methodology for the evaluation of geological model constructed in Phase I could be presented.
Tokuyasu, Shingo; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Tagami, Masahiko; Kurihara, Arata
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Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Tagami, Masahiko; Hodotsuka, Yasuyuki; Hayakawa, Masashi; Kurihara, Arata; Hayano, Akira; Yuguchi, Takashi
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Tagami, Masahiko; Nakamata, Kiminori*; Hayano, Akira; Kurihara, Arata; Amano, Kenji; Tsuruta, Tadahiko
no journal, ,
no abstracts in English
Kurihara, Arata; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Hayakawa, Masashi; Tagami, Masahiko; Hodotsuka, Yasuyuki; Yuguchi, Takashi; Ochi, Minoru; Tokuyasu, Shingo
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Tagami, Masahiko; Tsuruta, Tadahiko; Matsuoka, Toshiyuki
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Property and extent of a fault greatly influence the underground water-flow. It is important to understand the local tectonic history to predict prospective fault activity. This draft reports paleo-stress analysis of the Main Shaft Fault in Mizunami Underground Research Laboratory. Horizontal slicken-lines are widely observed on the fault gouge plane. The sense of movement was judged in every gouge sample. The multiple inverse method (Yamaji, 2000) is used to analyze paleo-stresses. The results show horizontal N-S trend maximum main stress and E-W trend minimum main stress. The Main Shaft Fault moved right-laterally when the basic dyke intrusion was occurred at 65 Ma. It was thought that NW directed Pacific plate subduction was parallel to the compressive paleo-stress at that time.
