Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 24

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

3D geostatistical modeling of fracture system in a granitic massif to characterize hydraulic properties and fracture distribution

Koike, Katsuaki*; Kubo, Taiki*; Liu, C.*; Masoud, A.*; Amano, Kenji; Kurihara, Arata*; Matsuoka, Toshiyuki; Lanyon, B.*

Tectonophysics, 660, p.1 - 16, 2015/10

 Times Cited Count:20 Percentile:68.73(Geochemistry & Geophysics)

This study integrates 3D models of rock fractures from different sources and hydraulic properties aimed at identifying relationships between fractures and permeability. A geostatistical method (GEOFRAC) that can incorporate orientations of sampled data was applied to 50,900 borehole fractures for spatial modeling of fractures over a 12 km by 8 km area, to a depth of 1.5 km. GEOFRAC produced a plausible 3D fracture model, in that the orientations of simulated fractures correspond to those of the sample data and the continuous fractures appeared near a known fault. Small-scale fracture distributions with dominant orientations were also characterized around the two shafts using fracture data from the shaft walls. By integrating the 3D model of hydraulic conductivity using sequential Gaussian simulation with the GEOFRAC fractures from the borehole data, the fracture sizes and directions that strongly affect permeable features were identified.

Journal Articles

3D hydraulic conductivity modeling of fractured granitic body using geostatistical techniques and its application to regional groundwater flow analysis

Kubo, Taiki*; Koike, Katsuaki*; Liu, C.*; Kurihara, Arata*; Matsuoka, Toshiyuki

Chigaku Zasshi, 122(1), p.139 - 158, 2013/03

Numerical simulations have been the most effective method for estimating flow pattern, flux, and flow velocity of the groundwater to precisely characterize large-scale groundwater systems. Spatial modeling of the 3D distribution of hydraulic conductivity over a study area is indispensable to obtain accurate simulation results. However, such spatial modeling is difficult in most cases due to the limitations of hydraulic conductivity data in terms of their volume and location. To overcome these problems and establish an advanced technique, we adopt geostatistics and combine a fracture distribution model with measured conductivity data, selecting the Tono area situated in Gifu Prefecture, central Japan for the field study. The size of the main target area covers 12 km (E-W) by 8 km (N-S), with a depth range of 1.5 km, and it is chiefly underlain by Cretaceous granite. Because the distribution of 395 hydraulic test data acquired along the 25 deep boreholes was biased, the data values were compared to the dimensions of simulated fractures using GEOFRAC. As a result, a positive correlation was identified. Using a regression equation for the correlation, hydraulic conductivity values were assigned to every simulated fracture. Then, a sequential Gaussian simulation (SGS) was applied to construct a 3D spatial model of hydraulic conductivity using those assumed values and actual test data. The plausibility of the resulting model was confirmed through the continuity of high and low permeable zones. The next step is a groundwater flow simulation using MODFLOW and the model. The simulation results were regarded to be appropriate because distribution of hydraulic head, locations of major discharge points, and anisotropy of hydraulic behavior of the Tsukiyoshi fault correspond to the results of observations.

Journal Articles

Geological investigations for geological model of deep underground geoenvironment at the Mizunami Underground Research Laboratory (MIU)

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.

JAEA Reports

Development of geological models in the Mizunami Underground Research Laboratory Project; Updating from "Shaft180 geological model" to "Stage300 geological model" in Phase 2

Ishibashi, Masayuki; Kurihara, Arata*; Matsuoka, Toshiyuki; Sasao, Eiji

JAEA-Research 2012-018, 48 Pages, 2012/07

JAEA-Research-2012-018.pdf:8.48MB
JAEA-Research-2012-018(errata).pdf:1.13MB
JAEA-Research-2012-018-appendix(CD-ROM).zip:13.81MB

This document presents about updating of geological models at the Phase 2 in the Mizunami underground research laboratory project. In the phase 2, the geological models has been updated four times (Shaft180 geological model, Pilot500 geological model, Sustage200 geological model, Stage300 geological model) based on geological mapping date and/or some borehole investigation data at the shafts and research galleries. These geological models represent distributions of lithofacies and/or geological structures based on each geological investigation. In order to evaluate relationship between understanding of geological environments and progress of investigations, to organize the history of geological models updating is important.

JAEA Reports

Study on hydrogeology on the Mizunami Underground Research Laboratory Project; Groundwater flow and particle tracking simulation on site scale

Kosaka, Hiroshi; Saegusa, Hiromitsu; Kurihara, Arata*; Onoe, Hironori

JAEA-Research 2012-012, 100 Pages, 2012/07

JAEA-Research-2012-012.pdf:17.95MB

In this study, groundwater flow and particle tracking simulations using hydrogeological models have been carried out in order to evaluate the relationship between understanding of groundwater flow characteristics and the amount of information that is increased by the progress of investigations. The influences of difference of the method for interpretation of hydrogeology have been also evaluated. As a result, uncertainties of the groundwater flow characteristics were decreased by increasing the amount of information. It was also found that the distribution of large-scale discrete features and the heterogeneity of groundwater flow characteristics affect the groundwater flow characteristics. Furthermore, the method to identify the target of further investigation and to make plan for the investigation were proposed.

Journal Articles

Geostatistic analysis for groundwater flow and hydraulic parameters in deep granitic body

Kubo, Taiki*; Koike, Katsuaki*; Kurihara, Arata*; Matsuoka, Toshiyuki

Heisei-23 Nendo (2011 Nen) Shigen, Sozai Gakkai Shuki Taikai Koenshu, p.369 - 370, 2011/09

no abstracts in English

JAEA Reports

Study on Geology on Mizunami Underground Research Laboratory Project; Annual report for fiscal year 2008

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.

Journal Articles

Characterization and tectonic significance of low-angle fracture distribution in the upper part of a granite body; New insight from the Toki Granite around the Mizunami Underground Research Laboratory (MIU), central Japan

Kurihara, Arata; Amano, Kenji; Liu, C.*; Koike, Katsuaki*

Journal of MMIJ, 124(12), p.710 - 718, 2008/12

The spatial distribution of hydrogeologically-relevant geological structures such as fracture and fault is usually very heterogeneous, varying, in general, according to geological history, scale of observation and rock type. With the objective of improving analytical methods to better understand structural heterogeneities, this paper describes the results of investigations of the spatial relationship between regional geological structures (Tsukiyoshi fault and Tsukiyoshi paleo-channel) and fracture density with special emphasis on low-angle fractures in the Toki granite, central Japan. As a result of the analysis, positive correlations between average of fracture spacing data and the horizontal distances from two regional geological structures have been observed. Because the positive correlations can be approximated with a polynomial function of the response surface, we have obtained an improved understanding of the spatial distribution of low-angle fractures with respect to the location of regional geological structures. We have interpreted that the observed spatial distribution of low-angle fracture density conforms to the tectonic setting, on the assumption that the Tsukiyoshi fault and Tsukiyoshi paleo-channel are probably associated with the pull-apart basin by strike-slip faulting from the past investigations and geophysical surveys for this research area. In addition, the proposed spatial modeling techniques and geological interpretations are able to evaluate certainty of interpreted faults and fractures distributions, quantify general trend in structural heterogeneities and detect unknown faults.

Journal Articles

Overview of national centralized tokamak program; Mission, design and strategy to contribute ITER and DEMO

Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.

Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12

To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.

Journal Articles

Overview of the national centralized tokamak programme

Kikuchi, Mitsuru; Tamai, Hiroshi; Matsukawa, Makoto; Fujita, Takaaki; Takase, Yuichi*; Sakurai, Shinji; Kizu, Kaname; Tsuchiya, Katsuhiko; Kurita, Genichi; Morioka, Atsuhiko; et al.

Nuclear Fusion, 46(3), p.S29 - S38, 2006/03

 Times Cited Count:13 Percentile:44.28(Physics, Fluids & Plasmas)

The National Centralized Tokamak (NCT) facility program is a domestic research program for advanced tokamak research to succeed JT-60U incorporating Japanese university accomplishments. The mission of NCT is to establish high beta steady-state operation for DEMO and to contribute to ITER. The machine flexibility and mobility is pursued in aspect ratio and shape controllability, feedback control of resistive wall modes, wide current and pressure profile control capability for the demonstration of the high-b steady state.

Journal Articles

Engineering design and control scenario for steady-state high-beta operation in national centralized tokamak

Tsuchiya, Katsuhiko; Akiba, Masato; Azechi, Hiroshi*; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; et al.

Fusion Engineering and Design, 81(8-14), p.1599 - 1605, 2006/02

 Times Cited Count:1 Percentile:10.64(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Design study of national centralized tokamak facility for the demonstration of steady state high-$$beta$$ plasma operation

Tamai, Hiroshi; Akiba, Masato; Azechi, Hiroshi*; Fujita, Takaaki; Hamamatsu, Kiyotaka; Hashizume, Hidetoshi*; Hayashi, Nobuhiko; Horiike, Hiroshi*; Hosogane, Nobuyuki; Ichimura, Makoto*; et al.

Nuclear Fusion, 45(12), p.1676 - 1683, 2005/12

 Times Cited Count:15 Percentile:48.09(Physics, Fluids & Plasmas)

Design studies are shown on the National Centralized Tokamak facility. The machine design is carried out to investigate the capability for the flexibility in aspect ratio and shape controllability for the demonstration of the high-beta steady state operation with nation-wide collaboration, in parallel with ITER towards DEMO. Two designs are proposed and assessed with respect to the physics requirements such as confinement, stability, current drive, divertor, and energetic particle confinement. The operation range in the aspect ratio and the plasma shape is widely enhanced in consistent with the sufficient divertor pumping. Evaluations of the plasma performance towards the determination of machine design are presented.

Oral presentation

Fracture distribution modeling for understanding of water-conducting features

Koike, Katsuaki*; Liu, C.*; Amano, Kenji; Kurihara, Arata

no journal, , 

The object of this research is a development of modelling methods for three-dimensional fracture distribution. Our research area is Tono region in Gifu prefecture, and we performed the three-dimensional fracture distribution modeling by using borehole data and the fracture distribution analysis code (GEOFRAC) based on geostatistical methods in this area. As a results, we recognaized that fractures matched with the sudden change part of these physical properties have water-conducting feature by overlapping three-dimensional fracture distribution with distribution data of resistivity, p-wave velocity and fracture filling materials.

Oral presentation

Geological structures in upper part of granite in the Mizunami Underground Research Laboratory

Tagami, Masahiko; Nakamata, Kiminori*; Hayano, Akira; Kurihara, Arata; Amano, Kenji; Tsuruta, Tadahiko

no journal, , 

no abstracts in English

Oral presentation

Mizunami URL project, geological investigations

Tsuruta, Tadahiko; Amano, Kenji; Matsuoka, Toshiyuki; Tagami, Masahiko; Hodotsuka, Yasuyuki; Hayakawa, Masashi; Kurihara, Arata; Hayano, Akira; Yuguchi, Takashi

no journal, , 

no abstracts in English

Oral presentation

Estimation of fracture density distribution in a granite body based on geological investigation and interpretation; A Case study of data from boreholes around the Mizunami Underground Research Laboratory, central Japan

Kurihara, Arata; Amano, Kenji; Koike, Katsuaki*; Liu, C.*

no journal, , 

The spatial distribution of hydrogeologically-relevant geological structures such as fracture and fault is usually very heterogeneous, varying, in general, according to geological history, scale of observation and rock type. With the objective of improving analytical methods to better understand structural heterogeneities, this paper describes the results of investigations of the spatial relationship between regional geological structures (Tsukiyoshi fault and Tsukiyoshi paleo-channel) and fracture density with special emphasis on low-angle fractures in the Toki granite, central Japan. As a result of the analysis, positive correlations between average of fracture spacing data and the horizontal distances from two regional geological structures have been observed. Because the positive correlations can be approximated with a polynomial function of the response surface, we have obtained an improved understanding of the spatial distribution of low-angle fractures with respect to the location of regional geological structures. We have interpreted that the observed spatial distribution of low-angle fracture density conforms to the tectonic setting, on the assumption that the Tsukiyoshi fault and Tsukiyoshi paleo-channel are probably associated with the pull-apart basin by strike-slip faulting from the past investigations and geophysical surveys for this research area. In addition, the proposed spatial modeling techniques and geological interpretations are able to evaluate certainty of interpreted faults and fractures distributions, quantify general trend in structural heterogeneities and detect unknown faults.

Oral presentation

A Proposed method of multi-scale modeling of fractures and hydraulic properties in geologic media

Koike, Katsuaki*; Liu, C.*; Masoud, A.*; Amano, Kenji; Kurihara, Arata

no journal, , 

no abstracts in English

Oral presentation

Mizunami Underground Laboratory project; Investigation of geology

Kurihara, Arata; Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Hayano, Akira; Hayakawa, Masashi; Tagami, Masahiko; Hodotsuka, Yasuyuki; Yuguchi, Takashi; Ochi, Minoru; Tokuyasu, Shingo

no journal, , 

no abstracts in English

Oral presentation

Development for spatial modeling of geological structure; A Case study of the Mizunami Underground Research Laboratory

Tsuruta, Tadahiko; Matsuoka, Toshiyuki; Tagami, Masahiko; Kurihara, Arata; Amano, Kenji; Yamada, Yasuhiro*; Koike, Katsuaki*

no journal, , 

no abstracts in English

Oral presentation

Spatial modeling of large-scale hydraulic structures in a granite area with consideration on relation to fracture distributions

Kurihara, Arata; Koike, Katsuaki*; Liu, C.*; Masoud, A.*; Amano, Kenji

no journal, , 

In this study, we constructed the spatial model for permeability and water-quality distribution in an analytical area (L = 12 km, W = 8 km, H = 1.5 km), with an existing Multi-scale Modeling method used for geology in Tono area. We recognized that a part of lineaments over 2 km length locate on a boundary between permeability or water-quality divisions from comparing these models with an existing fracture distribution model. Multi-scale Modeling method used for this study can be applied for a method to predict heterogeneous hydraulic structures distribution in rocks.

24 (Records 1-20 displayed on this page)