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Sanada, Masanori; Kishi, Hirokazu*; Sugita, Yutaka; Hayashi, Katsuhiko*; Takebe, Atsuji*; Okubo, Seisuke*
JAEA-Research 2012-025, 130 Pages, 2012/09
JAEA-Research-2012-025.pdf:4.12MB
In this study, strength recovery, generalized stress relaxation and two tensile strength tests were carried out using shale sampled in the Wakkanai-formation. As the results, by using the value of a suitable constant with the constitutive equation showing strength recovery, it was showed that change of the axial stress in a compacting test could be expressed. About the generalized relaxation, it examined by the air dried and the saturated condition. Visco-elastic behavior was more remarkable in saturated condition than the air dried. Moreover, when the loading rate up to the starting point of the generalized relaxation test was large, the influence on visco-elastic behavior was remarkable. About tensile characteristics, a splitting tensile strength test and a uniaxial tensile strength test were carried out. About splitting tensile strength, it turned out that the influence of the loading direction on a bedding plane is great.
Sanada, Masanori; Kishi, Hirokazu; Hayashi, Katsuhiko*; Takebe, Atsuji*
JAEA-Research 2011-055, 79 Pages, 2012/03
JAEA-Research-2011-055.pdf:4.11MB
In order to refine and rationalize a design method of multi tunnels in the deep geological repository, various study have been conducted. In this study, an effect of procedure for excavating multi-tunnels on extent of EDZ was examined by 3D FEM analysis. In modeling the multi tunnels and setting cases of analysis, workability, cost and safeness under construction were considered. Results of 3D FEM analysis showed that 3D effect of procedure for excavating such as a gap of progress with tunnel faces can be considered by 3D FEM and extent of EDZ is demonstrated more practically compared with 2D FEM. Another 2D FEM analysis modeling for crystalline rock (granite) was executed and the results showed that plastic zone did not appear in all cases.
Sanada, Masanori; Hayashi, Katsuhiko*; Kishi, Hirokazu; Takebe, Atsuji*; Okubo, Seisuke*
JAEA-Research 2011-028, 102 Pages, 2011/11
JAEA-Research-2011-028.pdf:3.08MB
In this study, strength recovery, generalized stress relaxation and two tensile strength tests were carried out using shale sampled in the Wakkanai-formation. As the results, recovery of failed rocks in strength and hydraulic conductivity were observed under a certain condition. We believe this result is very important for the stability evaluation of underground space in the bedrock that needs good sealing up characteristic, isolation characteristic, safety and high reliability for long term. Generalized stress relaxation test was conducted submerging samples in water. Experimental results showed comparatively smaller scatter than those in air-dried condition. It was also found that testing results were affected by strain rate up to the starting point of generalized relaxation test. Indirect and uniaxial tensile strength tests were also conducted submerging samples in water and smaller tensile strength with smaller scatter were obtained than those in air-dried condition.
Sakaguchi, Shinobu; Tachibana, Ikuya; Koshino, Katsuhiko; Shirozu, Hidetomo; Shirai, Nobutoshi; Imamoto, Nobuo; Tomita, Tsuneo; Tobita, Hiroo; Yamanaka, Atsushi; Kobayashi, Daisuke; et al.
JAEA-Technology 2011-006, 24 Pages, 2011/03
JAEA-Technology-2011-006.pdf:3.07MB
In the Niigataken Chuetsu-oki Earthquake on 2007, observed earthquake motion exceeded design base at the Kashiwazaki Kariwa nuclear plant. However, there was no earthquake damage in safety important equipments to stop reactor, to cool reactor, and to contain radioactive materials. One of this reason is said that many safety margin are included in the design and the permissible value. To know more accurate safety margin, shearing force examinations for the base bolts were conducted. In examinations, delegate test-bolts were made; the test bolts were selected from heavier equipment in Tokai Reprocessing Plant. In this report, the shearing strength obtained from the examinations shows more accurate safety margin.
Hayashi, Katsuhiko; Kishi, Hirokazu; Kabayashi, Yasushi*; Takebe, Atsuji*; Fujiyama, Tetsuo*; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2010-059, 92 Pages, 2011/03
JAEA-Research-2010-059.pdf:3.71MB
In this study, the first investigation is the order of the multi-tunnels excavation. The second is the strain-softening model for multi-tunnels which is based on test data at Horonobe site. As results of first investigation, we showed as 2 dimensional analyses that it was desirable to excavate the tunnel of the remote distance at first and excavate the tunnel between these tunnels next, and it is necessary for the examination that reflected a real plan, such as evacuation machine and actual multi tunnel layout. As the results of second investigation, we also showed the more reliable EDZ by using the strain-softening model that is based on test data at Horonobe site. Furthermore, we standardized the design method (draft) for the practical use by referring the past studies of multi tunnel design method.
Hayashi, Katsuhiko; Noguchi, Akira; Kishi, Hirokazu; Kabayashi, Yasushi*; Nakama, Shigeo; Fujita, Tomoo; Naito, Morimasa; Tada, Hiroyuki*; Kumasaka, Hiroo*; Goke, Mitsuo*; et al.
JAEA-Research 2010-057, 101 Pages, 2011/03
JAEA-Research-2010-057.pdf:7.47MB
Cement-type materials that are used for supports or grouting at high-level radioactive waste disposal facilities leach into the groundwater and create a highly alkaline environment. Of concern in highly alkaline environments are the alteration of bentonite used as buffers or backfill materials, and of surrounding rock mass, and the increased uncertainty regarding the provision of performance of the disposal system over a long period of time. In this study, to reduce the quantity of cement-type materials that cause highly alkaline environments, technical feasibility of the support structure including the materials which considered the long-term performance of the HLW disposal system are discussed by using knowledge and technology accumulated in JAEA and Shimizu Construction. Moreover, based on the results, the problems remained in the application to the future HLW disposal institution are summarized.
Hayashi, Katsuhiko; Kishi, Hirokazu; Kabayashi, Yasushi*; Takebe, Atsuji*; Okubo, Seisuke*
JAEA-Research 2009-058, 106 Pages, 2010/02
JAEA-Research-2009-058.pdf:18.82MB
In this study, experimental studies on the strength recovery, the generalized stress relaxation behavior and the tensile strength were conducted using samples obtained from the Wakkanai-formation shale. As the results, the strength recovery has time-dependent characteristics. It was founded that the generalized stress relaxation behavior depends on the draining conditions. Furthermore, regarding the tensile strength, complete stress-strain curve under uniaxial tensile strength conditions was gotten and it was found that there is small residual strength. The results of uniaxial tensile strength in this year are almost same as the minimum value of splitting tensile strength test results.
Hayashi, Katsuhiko; Kishi, Hirokazu; Kabayashi, Yasushi*; Takebe, Atsuji*; Fujiyama, Tetsuo*; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2009-056, 86 Pages, 2010/02
JAEA-Research-2009-056.pdf:9.96MB
In this study, the effect of constitutive models such as strain softening of rock masses for EDZ, and the stress relief ratio used for multi tunnels analysis were conducted. As the result, it is necessary to confirm mechanical behavior of in situ rock and it is important to choose suitable constitutive models, and it is possible for all tunnels in multi tunnels model to have same stress relief ratio.
Hayashi, Katsuhiko; Kobayashi, Yasushi; Hiramoto, Masayuki*; Mizutani, Kazuhiko*; Morita, Atsushi*
JAEA-Research 2009-016, 127 Pages, 2009/08
JAEA-Research-2009-016.pdf:5.23MB
"Study on configuration of analytical domain of the multi tunnels model" and "Remainders on an elasto-plastic FEM (Finite Element Method) analysis" in case of the full width of pillar become plastic on simplified model" are studied as "The study on the enhanced reliability of elasto-plastic FEM". In addition, "The effect of rock support and consolidation of the host rock to control the plastic region" was conducted as "The study on the mechanical stability of tunnels". As the results, it was seen that the analytical domain should be assigned 3-5W (W: width of multi tunnels) for a horizontal side from the endmost tunnel and 3-4W for below of the tunnels. It was found reasonable and proper on the elasto-plastic FEM analysis that the analysis domain must be large enough not to have plastic deformation in all analysis of domains under the condition in which the full width of pillar has plastic deformation. It was also found that the ground support suppresses the plasticity domain as the ground support effect. It was acknowledged that the auxiliary construction method by improvement of the ground has the suppression effect of the plasticity domain applying to the multi tunnels.
Iwatsuki, Teruki; Sato, Haruo; Tanai, Kenji; Inagaki, Manabu; Sawada, Atsushi; Niinuma, Hiroaki; Ishii, Eiichi; Maekawa, Keisuke; Tomura, Goji; Sanada, Hiroyuki; et al.
JAEA-Research 2009-002, 156 Pages, 2009/05
JAEA-Research-2009-002.pdf:12.86MB
The research and development plan for geological investigation, engineering technology and safety assessment during the drilling of a shaft down to intermediate depth are summarized according to the Midterm Plan till 2009 Fiscal year of JAEA. This report describes subject, current status and programme in the "Phase 2: Construction phase" (investigations during construction of the underground facilities). Furthermore regarding R&D plan in next Midterm Plan of JAEA, preliminary ideas are summarized.
Okubo, Seisuke*; Hayashi, Katsuhiko; Kobayashi, Yasushi; Hiramoto, Masayuki*
JAEA-Research 2008-106, 91 Pages, 2009/02
JAEA-Research-2008-106.pdf:6.08MB
It is generally known that the rock has the properties of strength recovery by elapse of time around the tunnel inside sedimentary rock with ground support due to inner pressure and ground pressure. The properties of strength recovery must be taken into account of the estimation about cavity shape stability or the long-term dynamical behavior of closed disposal ground. Our research study is focusing on the properties of strength recovery, generalized relaxation behavior and the characteristics of tensile strength by experiments using boring cores obtained from the Horonobe Underground Research Laboratory so as to improve the modeling for future stage.
*; Tomimitsu, Hiroshi; *; *; *; Aizawa, Kazuya; Okayasu, Satoru; *; Kazumata, Yukio*; Y.C.Jiang*; et al.
Japanese Journal of Applied Physics, Part 1, 36(12A), p.7296 - 7301, 1997/12
Times Cited Count：6 Percentile：36.78(Physics, Applied)no abstracts in English
Seki, Yasushi; Takatsu, Hideyuki; Iida, Hiromasa; *; Ogawa, Masuro; Noguchi, Hiroshi; Murata, Mikio; *; *; *; et al.
JAERI-M 91-126, 511 Pages, 1991/08
no abstracts in English
*; *; *; Kawai, Masayoshi*; *; Yamaoka, Mitsuaki*; *; Seki, Yasushi
JAERI-M 88-251, 303 Pages, 1988/12
no abstracts in English
; ; *; ; Hirabayashi, F.*; *; *; *; *; *; et al.
JAERI-M 9859, 78 Pages, 1982/01
no abstracts in English
*; ; ; ; ; ; ; ;
Dai-2-Kai Genshiryoku Shimpojiumu Hobunshu, P. 173, 1958/00
no abstracts in English
Hayashi, Katsuhiko; Kishi, Hirokazu; Takebe, Atsuji*
no journal, ,
The geological disposal facility for high-level radioactive waste has the new structure that consists of many tunnels in parallel (multi tunnels). Our organization designed this facility by using single tunnel model at the beginning, however we realized that this method can not predict where is Excavation disturbed zone that is caused by excavation as multi tunnels characteristics. Now we are investigating the new design methodology with multi tunnel models that takes into account of their behavior for improving design accuracy.
Saito, Akira*; Goke, Mitsuo*; Nakaya, Atsushi*; Tada, Hiroyuki*; Hayashi, Katsuhiko; Noguchi, Akira; Kishi, Hirokazu; Nakama, Shigeo
no journal, ,
We are supposing a low cement use tunner support made for granite rock block connecting low alkaline cement applying to HLW repositories. Because of the bending moment of the segment by dead load and the variance of the earth pressure, We made a model segment bending experiment to get a mechanical properties. The maximum load of the positive bending moment is around 210kN, which is around twice of the dead load of 117kN. The other hand, the maximum load in the negative bending moment is around 44kN, as same as the dead load. As the result of observating the cracks of the model segment, We found three or four cracks along the surface of the boundary of the rock block and mortar in the positive bending experiment. The other hand, we found only one crack at the center avoiding rock block in the negative bending experiment. Next, we will improve the construction method, prevention of the crack in the segment and the exfoliation of mortar and the steel panel.
Kumasaka, Hiroo*; Saito, Akira*; Nakaya, Atsushi*; Tada, Hiroyuki*; Hayashi, Katsuhiko; Noguchi, Akira; Kishi, Hirokazu; Nakama, Shigeo
no journal, ,
We are proposing to use the rock segment reducing the amount of the cementutious materials. In this report, we are getting young's modulus and poisson's ratio from the deformation experiment of the macadam mass, and performed a stability analysis of the gallery filled with macadam between the hostrock and the rock segment. We performed a alternating bearing test with high confirming pressure, and we estimated the Young's modulus and the poisson's ratio of the mass macadam from the result of the bearing test. After that, we performed the stability analysis of the galleries in the condition of the JAEA second report with the rock segment and the macadam. We found that the strain at the surface of the host rock is smaller than that of conventional one, and the stability of the host rock is remained, and the compressive stress in the rock segment is the half of the compressive strength of it. We considered that the rock segment support system is stable enough for the supporting system.
Hayashi, Katsuhiko; Kishi, Hirokazu; Takebe, Atsuji*
no journal, ,
The geological disposal facility for high-level radioactive waste has the new structure that consists of many tunnels in parallel (multi tunnels) at 300 m under the ground. Our organization designed this facility by using single tunnel model at the beginning, however we realized that this method can not predict where is excavation disturbed zone that is caused by excavation as multi tunnels characteristics. Now we are investigating the new design methodology with multi tunnel models that takes into account of their behavior for improving design accuracy.
