Development of in situ stress estimation method based on the measured convergence and geological observations

Kamemura, Katsumi*; Aoyagi, Kazuhei; Nago, Makito*; Sugawara, Kentaro*

Dai-45-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.43 - 48, 2018/01

In situ stress state is very important for 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 based on the measured convergence and detailed geological observations during gallery excavation. The convergence was measured in various directions of the loop gallery at 350m depth of the Horonobe URL; this allows determination of the stress state corresponding to the rock mass behavior in 120m 200m area. In situ stress state estimated by the back analysis considering existing faults and fractures showed a good agreement with that of estimated from hydraulic fracturing method.

Estimation of rock mass stress state based on the convergence measurement result during tunnel excavation

Kamemura, Katsumi*; Aoyagi, Kazuhei; Nago, Makito*; Sugawara, Kentaro*; Matsubara, Makoto*

Dai-14-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (Internet), 6 Pages, 2017/01

In the design of deep underground structures such as high-level radioactive waste disposal repositories, the estimation of rock mass stress state is important as well as the estimation of mechanical characteristics of rock mass. This study establishes a practical and effective method for estimating in situ stress based on the convergence measurement results obtained during gallery construction of URL. The convergence was measured in various directions of the URL loop gallery at 350 m depth, and this will allow determination of the stress state over a large area using a back analysis method. In order to improve the accuracy of initial stress estimation, the relationship between convergence measurement results and geological situation of existing fractures were studied. The analysis results show good agreement with the in situ stress state results reported in previous studies and confirm the applicability of the proposed method.

Estimation of initial stress based on the convergence measurement result during tunnel excavation

Kamemura, Katsumi*; Fujita, Tomoo; Aoyagi, Kazuhei; Nago, Makito*; Shirase, Mitsuyasu*; Sugawara, Kentaro*

Dai-44-Kai Gamban Rikigaku Ni Kansuru Shimpojiumu Koenshu (CD-ROM), p.109 - 114, 2016/01

How to estimate the initial stress state as well as a mechanical characteristic of rock mass is important in the design of deep underground structures. Some stress measurement methods using borehole, which methodology and evaluation method have been discussed in detail, are carried out if necessary. However, obtained results are often varying widely, so the evaluation of initial stress is difficult. Here, the initial stress state corresponding to the rock mass behavior of about 120m200m area is evaluated using the convergence measurement results during tunnel excavation in 350m depth. Analysed result corresponded to that of other method, so the validity of the proposed method was shown.

Relationship between rock mass properties and damage of a concrete lining during shaft sinking in the Horonobe Underground Research Laboratory Project

Tsusaka, Kimikazu; Inagaki, Daisuke; Nago, Makito*; Kamemura, Katsumi*; Matsubara, Makoto*; Shigehiro, Michiko*

Proceedings of ITA-AITES World Tunnel Congress 2013 (WTC 2013)/39th General Assembly, p.2014 - 2021, 2013/05

https://doi.org/10.1201/b14769-276

Japan Atomic Energy Agency (JAEA) has been constructing three shafts to a depth of 500 m in the Horonobe Underground Research Laboratory Project. In this study, in consideration of support patterns installed, a relationship between the rock mass properties and mechanical response to excavation was investigated in detail during the construction of the East Access Shaft below a depth of 250 m. Since the shaft has intersected several faults with the size greater than the shaft diameter, some amounts of rock spalling have occurred and cracks have severely developed in a concrete lining in highly fractured zones. The results of pre-excavation grouting were compared with the results of fracture mapping in the shaft wall obtained during the shaft sinking. Applicability of several support patterns installed to control massive spalling during the shaft sinking was also analysed using the results of geometry profiling of shaft wall using a three-dimensional laser scanner and convergence measurements. As a result, based the empirical relationships among the characteristics of rocks, dimension of spalling, damage of a concrete lining and support patterns, a flow chart for selection of span of a concrete lining was proposed to control its severe damage prior to shaft excavation.

None

Sugihara, Yutaka*; Kubota, Shigeru*; Yamamoto, Takuya*; Kamemura, Katsumi*; *; *

JNC TJ1400 2001-005, 383 Pages, 2003/03

JNC-TJ1400-2001-005.pdf:18.73MB

no abstracts in English

None

Sugihara, Kozo; Kamemura, Katsumi*; Ninomiya, Yasuo*

Doboku Gakkai Rombunshu, (589), p.239 - 251, 1998/03

None

A Study on the technique to measure and evaluate loosened zone due to tunnel excavation (II)

Ito, K.*; Kamemura, Katsumi*; Homma, N.*; Mikami, Tetsuji*; Aoki, Kenji*; Ishi, S.*

PNC TJ4449 89-003VOL1, 223 Pages, 1989/03

PNC-TJ4449-89-003VOL1.pdf:23.93MB

None

Data analysis of high-precision tiltmeters installed around the Horonobe underground research laboratory

Ijiri, Yuji*; Hatsuyama, Yoshihiro*; Nago, Makito*; Kamemura, Katsumi*; Sato, Masaru*; Sanoki, Satoru*; Kunimaru, Takanori

no journal, , 

Both the short- and long-period noises were filtered out from the data of high-precision tiltmeters installed at the Horonobe URL. Then, the effect of shaft excavation on these data was investigated.

The Project for grouting technology development for the high level radioactive waste repository, 8

Ijiri, Yuji*; Shindo, Akihisa*; Miura, Hitoshi*; Kamemura, Katsumi*; Tomoe, Naoto*; Nagai, Norihisa*; Abe, Akimasa*; Fujita, Tomoo; Izumi, Atsushi

no journal, , 

no abstracts in English