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Aoyagi, Kazuhei; Sugawara, Kentaro*; Kamemura, Katsumi*; Nago, Makito*
International Journal of Rock Mechanics and Mining Sciences, 178, p.105776_1 - 105776_11, 2024/06
Times Cited Count：0 Percentile：0.00(Engineering, Geological)A method for estimating the stress state during the construction of underground facilities such as deep geological disposal repositories is necessary to enhance the reliability of their design, construction, and long-term performance. For this purpose, numerous in situ measurements of variables such as hydraulic fracturing or the stress relief method have been typically performed to estimate the stress state. However, it is difficult in some cases to validate the stress state, particularly in sedimentary rock, because of the variation related to heterogeneous rock masses and topography. This study developed a new method for reliably estimating the in situ stress state of rocks using the measured initial elastic displacement of the loop gallery at 350 m depth in the Horonobe Underground Research Laboratory (URL), Japan. The estimated magnitudes of the maximum and minimum horizontal stresses are 11.25 and 6.25 MPa, respectively, which are similar to the stresses measured using the hydraulic fracturing method performed before excavating the facility. Although the proposed method could only be applied after excavation of the gallery in the studied case, it yielded an estimate of the stress state over a region of hundreds of square meters with high accuracy, as assessed by comparison with measured results. We conclude that the method can be applied to optimizing the design, construction, and performance of large underground facilities, such as deep geological repositories.
Aoyagi, Kazuhei; Sakurai, Akitaka; Miyara, Nobukatsu; Sugita, Yutaka; Tanai, Kenji
Shigen, Sozai Koenshu (Internet), 6(2), 7 Pages, 2019/09
no abstracts in English
Aoyagi, Kazuhei; Kamemura, Katsumi*; Sugawara, Kentaro*; Hagihara, Takeshi*
Dai-53-Kai Jiban Kogaku Kenkyu Happyokai Happyo Koenshu (DVD-ROM), p.11 - 12, 2018/07
no abstracts in English
Aoyagi, Kazuhei; Kamemura, Katsumi*; Nago, Makito*; Sugawara, Kentaro*; Matsubara, Makoto*
Proceedings of ITA-AITES World Tunnel Congress 2017 (WTC 2017) (USB Flash Drive), 10 Pages, 2017/06
An in situ stress state is one of the important factors in the design of deep underground facility of high-level radioactive waste disposal repository. This study establishes a practical and effective method for estimating in situ stress state on the basis of the measured convergence during gallery excavation. The convergence was measured in various directions of the loop gallery at 350m depth of the Horonobe Underground Research Laboratory; this allows determination of the stress state corresponding to the rock mass deformation behavior in an approximately 120 m* 200 m area. To estimate in situ stress state around that area, a back analysis method considering the existence of faults and fractures around the gallery was developed. The analyzed results showed a good agreement with the trend of in situ stress state estimated from hydraulic fracturing method.
Kuwabara, Kazumichi*; Aoyagi, Yoshiaki; Ozaki, Yusuke; Matsui, Hiroya
JAEA-Research 2017-002, 39 Pages, 2017/03
JAEA-Research-2017-002.pdf:3.58MB
Authors developed a displacement meter using optical fiber sensor. The displacement meter can be set at any locations in a borehole and guarantee the measurement accuracy up to 5MPa. Total twelve displacement meters were installed in three boreholes to measure the rock mass displacement during groundwater recovery test. The measurement of the rock mass displacement was stated on March, 27, FY 2014. During the first and second groundwater recovery experiments, compressive displacements were observed close to the closure test drift wall. Magnitude of the measured displacements, except vicinity of test drift wall, was smaller than that of calculated under the assumption of it is an isotropic elastic material.
Motoshima, Takayuki*; Yabuki, Yoshio*; Minamide, Masashi*; Nago, Makito*; Aoyagi, Kazuhei
Tonneru Kogaku Hokokushu (CD-ROM), 24, p.I_10_1 - I_10_5, 2014/12
Economic tunnel support design for Horonobe underground research laboratory was obtained according to the relationship in the direction of the initial stress and the direction of excavation. The authors compared between the in situ convergence results and calculated results in order to investigate the validity of initial stress measurements. As a result, a positive correlation was observed between the in situ convergence results and calculated results, and the difference between the two was able to be explained by the difference between the assumed deformation coefficient and the measured coefficient. From these results, the measurement results of the initial stress performed in the surface based investigation has been confirmed almost reasonable.
n diodes due to heavy ion irradiationHirao, Toshio; Laird, J. S.; Onoda, Shinobu; Shibata, Toshihiko*; Wakasa, Takeshi; Yamakawa, Takeshi; Abe, Hiroshi; Takahashi, Yoshihiro*; Onishi, Kazunori*; Ito, Hisayoshi
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.105 - 109, 2004/10
no abstracts in English
Takahashi, Yoshihiro*; Shibata, Toshihiko*; Murase, Yuji*; Onishi, Kazunori*; Hirao, Toshio; Kamiya, Tomihiro
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.111 - 114, 2004/10
no abstracts in English
Tsuchiya, Katsuhiko; Kizu, Kaname; Miura, Yushi; Ando, Toshinari*; Sakasai, Akira; Matsukawa, Makoto; Tamai, Hiroshi; Ishida, Shinichi
IEEE Transactions on Applied Superconductivity, 14(2), p.1427 - 1430, 2004/06
Times Cited Count：1 Percentile：11.44(Engineering, Electrical & Electronic)no abstracts in English
Uchida, Masahiro; Yoshino, Naoto
JNC TN8410 2001-016, 36 Pages, 2001/05
JNC-TN8410-2001-016.pdf:1.53MB
This technical report summarizes sampling of the natural rock including conductive fracture. Hydraulic test was conducted at the target fracture prior to excavation. Objective of the sample was to reproduce same transmissivity at LABROCK by adjusting normal stress. This report was originally compiled by PNC in october, 1993.
Uchida, Masahiro; Yoshino, Naoto
JNC TN8410 2001-015, 35 Pages, 2001/05
JNC-TN8410-2001-015.pdf:1.73MB
This technical report summarizes excavation and preparation of the natural rock block sample used in LABROCK. This report was originally compiled by PNC in March, 1993.
Koizumi, Satoshi; Inami, Toshiya
Macromolecules, 32(17), p.5613 - 5621, 1999/00
Times Cited Count：4 Percentile：23.29(Polymer Science)no abstracts in English
Koizumi, Satoshi
Physica B; Condensed Matter, 241-243, p.973 - 975, 1998/00
Times Cited Count：1 Percentile：11.49(Physics, Condensed Matter)no abstracts in English
Kimura, Takaumi; Kato, Yoshiharu; Yoshida, Zenko
Radiochimica Acta, 82, p.141 - 145, 1998/00
no abstracts in English
Kimura, Takaumi; Kato, Yoshiharu; Yoshida, Zenko
Journal of Nuclear Science and Technology, 34(7), p.717 - 719, 1997/07
Times Cited Count：1 Percentile：14.20(Nuclear Science & Technology)no abstracts in English
PNC TJ1412 97-002, 157 Pages, 1997/03
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