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Hama, Katsuhiro; Mikake, Shinichiro; Nishio, Kazuhisa; Matsuoka, Toshiyuki; Ishibashi, Masayuki; Sasao, Eiji; Hikima, Ryoichi*; Tanno, Takeo*; Sanada, Hiroyuki; Onoe, Hironori; et al.
JAEA-Review 2013-050, 114 Pages, 2014/02
JAEA-Review-2013-050.pdf:19.95MB
Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II and the Phase III in fiscal year 2012. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2012, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.
Yamamoto, Nobuyuki; Iwano, Keita*; Namikawa, Tadashi*; Morikawa, Seiji*; Seno, Shoji*; Tabei, Kazuto*; Toida, Masaru*; Yokota, Hideharu
JAEA-Research 2013-003, 252 Pages, 2013/06
JAEA-Research-2013-003.pdf:77.85MB
This study reconsiders rock's mechanical and hydrological parameters based on additional 
data given in this year, and conducts the mechanical-hydrological analysis using the Micromechanics-Based Continuum (MBC) model which can consider the behavior of fracture. The acquired analysis results are compared with actual test data such as drift convergence and hydraulic pressure around the drift. Then, following knowledge is obtained.
Mihara, Morihiro; Sato, Nobuyuki; Ono, Shintaro*; Morikawa, Seiji*
JAEA-Data/Code 2009-026, 114 Pages, 2010/03
JAEA-Data-Code-2009-026.pdf:15.21MB
This report shows the capability, incorporated mechanical model and sample calculation of MACBECE. MACBECE incorporated the non-liner elastic model for cement-based material, the elasto- viscoplastic model considering swelling of bentonite-based material and the visco-elastic model reported by Okubo for host-rock. Furthermore, MACBECE can consider chemical transition of bentonite-based and cement-based materials.
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).
Mori, Takayuki*; Morikawa, Seiji*; Tabei, Kazuto*; Iwano, Keita*; Nakajima, Makoto*
JNC TJ7400 2005-080, 216 Pages, 2005/03
JNC-TJ7400-2005-080.pdf:35.16MB
As a first step of Mizunami Underground Research Laboratory Plan (MIU plan), through the laboratory and borehole in-situ tests, JNC Tono Geoscience Center plans to constitute the comprehensive geological model and predicts the rock behaviors in excavating the shaft and gallery. These model and results leads to be reflected by the next step research projects.So far, the first step of MIU plan is coming to final stage, and the second step will start at next year in which the in-situ researches are planned through the excavation. In this study, the comprehensive geometrical model was drawn out through the first step data, and MBC model analysis was carried out to predict the rock mass behavior around the shaft and gallery. The following results are obtained. (1) With MIZ-1 borehole core, artificial joints, which are assumed to be produced by rock blasting, were formed through the Brazilian test. And through the rock shear test for these joints, these mechanical properties were obtained. (2) By examining the MIZ-1 borehole research data, Mizunami site was classified by mechanical and joint properties and the Geomechanical model were made up. (3) Through the MBC model, the shaft and gallery cases were analyzed which depend on the rock mass classification, Excavation Damaged Zone, and the direction of the galleries. These results showed that in most cases, the joint opening were little because of the rock stiffness, but by the existence of high inclined joints, the side wall of the galleries were damaged by the excavation.
Okutsu, Kazuo*; Morikawa, Seiji*; Shimbo, Hiroshi*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Murakami, Takeshi*; Aoyama, Yuji*
JNC TJ8400 2005-013, 117 Pages, 2005/02
JNC-TJ8400-2005-013.pdf:3.24MB
To integrate the system for evaluation of long-term hydraulic condition in near field of TRU waste disposal, the engineered barrier, which consists of bentonite buffer and cementitious materials, was employed in the series of laboratory tests. On the bentonite buffer, with the aim of investigating of the effect of (i) interlayer cation in bentonite, (ii) content of siliceous sand and (iii) the ionic strength of ground water on its mechanical and hydraulic properties, series of laboratory tests were conducted. The same lot of bentonite was used in the series of tests to obtain consistent data. In addition, the swelling test of the laminated bentonite with caliumization front was conducted for verification of the proposed constitutive model. On cementitious materials, the altered specimen that produced immersing was investigated the water permeation and also characteristics. The hardened cement paste specimens with W/C=40 to 105% were immersed into deionized water and alteration behavior under diffusion condition was investigated.
Okutsu, Kazuo*; Morikawa, Seiji*; Shimbo, Hiroshi*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Murakami, Takeshi*; Aoyama, Yuji*
JNC TJ8400 2005-012, 272 Pages, 2005/02
JNC-TJ8400-2005-012.pdf:7.05MB
To integrate the system for evaluation of long-term hydraulic condition in near field of TRU waste disposal, the engineered barrier, which consists of bentonite buffer and cementitious materials, was employed in the series of laboratory tests.On the bentonite buffer, with the aim of investigating of the effect of (i)interlayer cation in bentonite, (ii)content of siliceous sand and (iii)the ionic strength of ground water on its mechanical and hydraulic properties, series of laboratory tests were conducted. The same lot of bentonite was used in the series of tests to obtain consistent data. In addition, the swelling test of the laminated bentonite with caliumization front was conducted for verification of the proposed constitutive model.On cementitious materials, the altered specimen that produced immersing was investigated the water permeation and also characteristics. The hardened cement paste specimens with W/C=40 to 105% were immersed into deionized water and alteration behavior under diffusion condition was investigated.
Okutsu, Kazuo*; Morikawa, Seiji*; Taguchi, Katsunori*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Takase, Hiroyasu*; Aoyama, Yuji*
JNC TJ8400 2003-087, 199 Pages, 2004/02
JNC-TJ8400-2003-087.pdf:4.82MB
The system development for evaluating the long-term alteration of hydraulic field in near field was examined. The "Evidential Support Logic" for ensuring the long-term stability of the repository was developed and evaluated. Furthermore, the developed chemical/mechanical alteration action analysis system was verified and improved. The system was coupled for the long-term alteration evaluation analysis.
Okutsu, Kazuo*; Morikawa, Seiji*; Taguchi, Katsunori*; Kuroyanagi, Mikio*; Sahara, Fumihiro*; Takase, Hiroyasu*; Aoyama, Yuji*
JNC TJ8400 2003-086, 426 Pages, 2004/02
JNC-TJ8400-2003-086.pdf:11.01MB
The system development for evaluating the long-term alteration of hydraulic field in near field was examined. The "Evidential Support Logic" for ensuring the long-term stability of the repository was developed and evaluated. Furthermore, the developed chemical/mechanical alteration analysis system was verified and improved. The system was coupled for the long-term alteration evaluation analysis.
Mori, Takayuki*; Morikawa, Seiji*; Tabei, Kazuto*; Iwano, Keita*
JNC TJ7400 2004-006, 58 Pages, 2004/02
JNC-TJ7400-2004-006.pdf:9.51MB
JNC Tono Geoscience Center planed a comprehensive geoscientific research program for the construction of an underground research laboratory in order to conduct the research and evaluation of geological environment. So far, based on mechanical data from 1,000-m borehole tests, several numerical analysis models, which consider the behavior of joints in a rock mass, have been applied to this site, and the discontinuous rock behavior around the shafts and galleries has been predicted.However, none of these analyses considered the "Excavation Damaged Zone". In this study, in order to grasp the extent of the Excavation Disturbed Zone, MBC analysis considering the Excavation Damaged Zone was carried out and the following results were obtained. 1.Using several parameters relevant to the rock and joints, a parametric study was performed to verify the effect on and sensitivity of the behavior of the Excavation Disturbed Zone. The results showed that joint frequency and Young's modulus of the rock were much effective parameters. 2.Based on the parametric study, several analyses for shaft and gallery were conducted. As the joint density increased and the area of the Excavation Damaged Zone expanded, the joint opening area increased and the equivalent shear stiffness decreased. 3.Two contrasting cases were also analyzed: one was assumed that pre-existing joints progress in the Excavation Damaged Zone, and the other assumed that joints tangential to the excavation wall are generated in the Excavation Damaged Zone. It was found that Excavation Damaged Zone tends to be larger in the former case than the latter case. 4.From these results, prediction analysis for Excavation Disturbed Zone considering the Excavation Damaged Zone was found to be practical. Through the in-situ monitoring data for shafts and galleries, the validity of these analyses will be verified.
Okutsu, Kazuo*; Morikawa, Seiji*; Takamura, Hisashi*; Hane, Koji*; Tabei, Kazuto*; Sahara, Fumihiro*; Murakami, Takeshi*
JNC TJ8400 2003-050, 140 Pages, 2003/02
JNC-TJ8400-2003-050.pdf:3.13MB
The system development for evaluating long-term alteration of hydraulic field in Near Field was examined.
Okutsu, Kazuo*; Morikawa, Seiji*; Takamura, Hisashi*; Hane, Koji*; Tabei, Kazuto*; Sahara, Fumihiro*; Murakami, Takeshi*
JNC TJ8400 2003-049, 265 Pages, 2003/02
JNC-TJ8400-2003-049.pdf:7.88MB
The system development for evaluating long-term alteration of hydraulic field in Near Field was examined.
Fukazawa, E.*; Tanaka, M.*; Yamamoto, H.*; Taira, K.*; Yamamoto, M.*; Okutsu, Kazuo*; Hane, Koji*; Aoyagi, Takayoshi*; Morikawa, Seiji*; Furuichi, Mitsuaki*
PNC TJ1100 98-007, 60 Pages, 1998/02
None
Fukazawa, E.*; Tanaka, M.*; Yamamoto, H.*; Taira, K.*; Yamamoto, M.*; Okutsu, Kazuo*; Hane, Koji*; Aoyagi, Takayoshi*; Morikawa, Seiji*; Furuichi, Mitsuaki*
PNC TJ1100 98-006, 434 Pages, 1998/02
None
; *; Fukazawa, E.*; Yamamoto, H.*; Taira, K.*; Tanaka, Toshiyuki*; Suyama, Yasuhiro*; Kondo, Y.*; *; *; et al.
PNC TJ1100 97-002, 85 Pages, 1997/03
None
Sanada, Hiroyuki; Sugita, Yutaka; Kunimaru, Takanori; Iwano, Keita*; Morikawa, Seiji*; Seno, Shoji*; Namikawa, Tadashi*
no journal, ,
no abstracts in English
Yabuuchi, Satoshi; Kunimaru, Takanori; Iwano, Keita*; Morikawa, Seiji*; Namikawa, Tadashi*
no journal, ,
no abstracts in English