Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Takeuchi, Ryuji; Tsuyuguchi, Koji*; Onoe, Hironori; Saegusa, Hiromitsu*; Beppu, Shinji
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 22(2), p.37 - 52, 2015/12
Assessment of the geological environment for the long term safety of geological disposal systems for high-level radioactive waste requires consideration for any phenomenon resulting in cumulative change to the geological environment at the regional scale. Groundwater pressure changes induced by earthquakes, for example, are one of the phenomena to be considered. Groundwater pressure changes induced by earthquakes have been observed during long-term monitoring carried out by Japan Atomic Energy Agency in the Tono Area, Gifu. In this paper, the observations of groundwater pressure change induced by earthquakes are summarized. In addition, an impact on groundwater flow conditions induced by earthquakes is discussed. In order to evaluate the long-term stability of groundwater flow condition, it is important to focus not only the change of groundwater pressure by earthquakes but also the change of the hydraulic gradient and hydraulic permeability.
Tsuyuguchi, Koji; Kuroiwa, Hiroshi; Kawamoto, Koji; Yamada, Nobuto; Onuki, Kenji; Iwatsuki, Teruki; Takeuchi, Ryuji; Ogata, Nobuhisa; Suto, Masahiro; Mikake, Shinichiro
JAEA-Technology 2013-044, 89 Pages, 2014/02
JAEA-Technology-2013-044.pdf:11.09MB
JAEA-Technology-2013-044-appendix(CD-ROM).zip:316.8MB
This document summarizes the data of pilot boreholes (12MI27, 12MI33) in the -500m Access/Research Gallery-North. The geological, hydraulic and geochemical data were obtained. In addition, groundwater monitoring system was installed in closure test gallery for the flooding test in phase III research. The results of investigation, biotite granite with medium to coarse-grained equigranular texture are characterized. Rock mass classification is B from CH class. Minor fault with fault gouge that was not presumed by an original model are observed in 12MI33. Density of fracture in 12MI27 near the Main-shaft fault tends to be compared to 12MI33. Water inflow in both boreholes is less. Permeability ranges from 4.8E-10 to 6.1E-09m/sec at the zone without alteration and with low inflow, from 1.1E-07 to 2.7E-07m/sec at the zone without alteration and with high inflow, respectively. Groundwater chemistry is rich in Na and Cl ion.
Shimo, Michito*; Kumamoto, So*; Tsuyuguchi, Koji; Onoe, Hironori; Saegusa, Hiromitsu; Mizuno, Takashi; Oyama, Takuya
JAEA-Research 2012-043, 98 Pages, 2013/03
JAEA-Research-2012-043.pdf:26.71MB
One of the goals of the Mizunami Underground Research Laboratory (MIU) Project is to develop technical basis for investigation, analysis and evaluation technologies for understanding the deep underground geological environment in various scales. Understanding groundwater flow system is one of the important issues in the project, and to achieve this purpose, technologies for hydrogeological model and groundwater flow simulation technique, have to be established. As a result of this study, the significant hydrogeological structures around the MIU Construction Site were estimated. The inflow rate into the MIU facilities and hydraulic and geochemical impacts around the MIU Construction Site caused by the MIU facilities construction were predicted. The effect of pre-grouting to the MIU facilities was also confirmed.
Niwa, Masakazu; Takeuchi, Ryuji; Onoe, Hironori; Tsuyuguchi, Koji; Asamori, Koichi; Umeda, Koji; Sugihara, Kozo
Geochemistry, Geophysics, Geosystems (Internet), 13(5), p.Q05020_1 - Q05020_15, 2012/05
Times Cited Count：14 Percentile：39.61(Geochemistry & Geophysics)In the 2011 off the Pacific coast of Tohoku Earthquake, groundwater pressure changes were observed in and around the Mizunami Underground Research Laboratory (MIU). Coseismic changes of groundwater pressure are believed to correspond to crustal dilation/contraction induced by earthquakes. In this study we calculated volumetric strain changes due to the Tohoku Earthquake. The calculation indicates 2
10
of dilational strain around the MIU. The dilation corresponds to drawdowns of several tens of centimeters or more, and is almost the same as the drawdown observed in the boreholes at distances greater than 1 km from the MIU. In contrast, rapid elevation of groundwater pressures was observed in the boreholes within the 500 m vicinity of the MIU. The anomalous elevation is explained by a temporary recovery of the drawdown due to excavation of the shafts and a unique permeability increase induced by the coseismic dilation of impervious faults.
Onoe, Hironori; Takeuchi, Ryuji; Takeda, Masaki; Daimaru, Shuji; Karino, Tomoyuki; Tsuyuguchi, Koji
no journal, ,
In this paper, a part of the result of long-term monitoring, hydrogeological modeling and groundwater flow simulation in Phase 2 of MIU project were introduced. And, applicability of model calibration methodology based on the data of hydraulic impacts in Phase 2 was confirmed by groundwater flow modeling using Phase 2 data.
Tsuyuguchi, Koji; Onoe, Hironori; Niwa, Masakazu; Takeuchi, Ryuji; Karino, Tomoyuki
no journal, ,
In the 2011 off the Pacific coast of Tohoku Earthquake, groundwater pressure changes were observed around the Mizunami Underground Research Laboratory (MIU) in Tono area. It was confirmed that the tendency of the pressure change due to the earthquake is different according to relationship with the location of borehole and geological feature structure. This report shows the water pressure change observed in boreholes after the earthquake.
Hagiwara, Hiroki; Tsuyuguchi, Koji; Takeuchi, Ryuji; Shingu, Shinya; Iwatsuki, Teruki
no journal, ,
no abstracts in English
Shingu, Shinya; Hagiwara, Hiroki; Omori, Kazuaki; Fukuda, Akari; Tsuyuguchi, Koji; Iwatsuki, Teruki
no journal, ,
no abstracts in English
Karino, Tomoyuki; Tsuyuguchi, Koji; Onoe, Hironori; Sato, Seiji; Onuki, Kenji; Takeuchi, Ryuji
no journal, ,
In this paper, a part of the result of long-term hydraulic pressure monitoring during the URL excavation in Phase 2 of MIU project were introduced. And, trend of long-term groundwater pressure changes of monitoring boreholes in and around the MIU construction site due to the 2011 off the Pacific coast of Tohoku Earthquake were introduced.
Tsuyuguchi, Koji; Onoe, Hironori; Takeuchi, Ryuji; Karino, Tomoyuki
no journal, ,
In the 2011 off the Pacific coast of Tohoku Earthquake, groundwater pressure changes were observed around the Mizunami Underground Research Laboratory (MIU) in Tono area. It was confirmed that the tendency of the pressure change due to the earthquake is different according to relationship with the location of borehole and geological feature structure. This report shows the water pressure change observed in boreholes after the earthquake.
Karino, Tomoyuki; Tsuyuguchi, Koji; Onoe, Hironori; Takeuchi, Ryuji
no journal, ,
Japan Atomic Energy Agency (JAEA) has been conducting Mizunami Underground Research Laboratory (MIU) Project. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of 20 years. Currently, the project is being carried out under the Phase II. One of the Phase II goals is set to develop and revise models of the geological environment using the investigation results obtained during excavation, and determine and assess the changes in the geological environment in response to excavation. The long term hydro-pressure monitoring has been continued to achieve the Phase II goals. In this paper, a part of the result of long-term hydro-pressure monitoring during the URL excavation in Phase 2 of MIU project were introduced.
Iwatsuki, Teruki; Sato, Toshinori; Takeuchi, Ryuji; Onoe, Hironori; Onuki, Kenji; Saegusa, Hiromitsu; Hasegawa, Takashi; Kuroiwa, Hiroshi; Tsuyuguchi, Koji; Ikeda, Koki; et al.
no journal, ,
Closure experiment of gallery of MIU is planned to understand the recovery process of geological environments after the closure. Flooding test gallery and monitoring boreholes are designed at 500 m access gallery to observe recovery of water pressure, chemistry around cement and burial materials, rock stress. Evaluation of numerical analysis methods on hydraulic, chemical and mechanical change will be conducted based on the results of upcoming closure experiment.
Tsuyuguchi, Koji*; Takeuchi, Ryuji; Onoe, Hironori; Sato, Seiji; Onuki, Kenji; Beppu, Shinji; Ogata, Nobuhisa
no journal, ,
no abstracts in English
