Post-earthquake rapid resealing of bedrock flow-paths by concretion-forming resin

Yoshida, Hidekazu*; Yamamoto, Koshi*; Asahara, Yoshihiro*; Maruyama, Ippei*; Karukaya, Koichi*; Saito, Akane*; Matsui, Hiroya; Mochizuki, Akihito; Jo, Mayumi*; Katsuta, Nagayoshi*; et al.

Communications Engineering (Internet), 3, p.67_1 - 67_10, 2024/05

https://doi.org/10.1038/s44172-024-00216-1

A capability to permanently seal fluid flow-paths through bedrock, like boreholes or underground tunnels, is needed to ensure the long-term safety and effectiveness of many underground activities e.g. CO storage, hydrocarbon field abandonment, and nuclear waste disposal. Commonly used cementitious seals may not be sufficiently durable due to chemical and physical degradation. Learning from natural calcite (CaCO) concretion formation, a more durable sealing method was developed using a "concretion-forming solvent". The method was tested by sealing flow-paths next to a tunnel in an underground research laboratory at 350 meters depth. The flow-paths initially sealed rapidly, then resealed after disturbance by earthquakes (M5.4). The treated rock recovered its very low natural permeability, demonstrating permanent sealing that is robust.

A Study of methods to prevent piping and erosion in buffer materials intended for a vertical deposition hole at the Horonobe Underground Research Laboratory

Jo, Mayumi*; Ono, Makoto*; Nakayama, Masashi; Asano, Hidekazu*; Ishii, Tomoko*

Geological Society Special Publications, 482, 16 Pages, 2018/09

https://doi.org/10.1144/SP482.7

An Investigation on mechanical properties of in-situ rock mass at the Horonobe Underground Research Laboratory

Tsusaka, Kimikazu*; Inagaki, Daisuke*; Niunoya, Sumio*; Jo, Mayumi*

Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 9 Pages, 2014/10

Consideration on poroelastic behavior of siliceous rock mass around an opening by stress-seepage coupled analysis

Sanada, Hiroyuki; Matsui, Hiroya; Yamamoto, Takuya*; Aoki, Tomoyuki*; Ogawa, Toyokazu*; Jo, Mayumi*; Fujii, Yoshiaki*

Heisei-19-Nendo Shigen, Sozai Gakkai Hokkaido Shibu Sokai Oyobi Shunki Koenkai Koen Yoshishu, p.9 - 10, 2007/06

Japan Atomic Energy Agency has been conducting the Horonobe Underground Reseach Laboratory Project as a part of geological isolation research and development at Horonobe-town in Hokkaido, Japan. The rocks around URL have high porosity and low permeability. Therefore, the excess pore pressure caused by URL excavation is possible to affect to the stability of surrounding rock. In this point of view, the authors carried out a stress-seepage coupled analysis to understand the process of the pore pressure change due to excavation and the influence to the stability of surrounding rock and support system. As a result, the large excess pore pressure causes a part in surrounding rock on excavation in an anisotropic initial stress condition and it dissipates with time. The pore pressure change causes the complex deformation in the surrounding rock as well. However, the phenomena are not significant influence to the stability of the surrounding rock and support system.

Investigation on time-dependent behavior of sedimentary rock (Phase 3)

Yamamoto, Takuya*; Aoki, Tomoyuki*; Jo, Mayumi*

JNC TJ5400 2005-002, 200 Pages, 2005/03

JNC-TJ5400-2005-002.pdf:42.65MB

For the rational design of the underground facility and for the safety during construction and operation it is necessary to consider the long-term stability of the rock mass around a drift. Especially, the time-dependent behavior of sedimentary rock is important because the mechanism of time-dipenednt is not well understood. Here, laboratory tests of rock specimens collected from the borehole investigation and numerical analysis on the stability of the rock mass around a drift were discussed for last two years. In this year, additional laboratory tests were performed to confirm the several important knowledges for last two years. Moreover, the preliminary numerical analysis was carried out to predict the EDZ due to excavation of underground facility.

Investigation on time-dependent behavior of sedimentary rock

Yamamoto, Takuya*; Aoki, Tomoyuki*; Taki, Haruo*; Jo, Mayumi*

JNC TJ5400 2003-001, 120 Pages, 2003/06

JNC-TJ5400-2003-001.pdf:14.04MB

none

Investigation on time-depedent behavior of sedimentary rock, 2

Yamamoto, Takuya*; Aoki, Tomoyuki*; Taki, Haruo*; Jo, Mayumi*

JNC TJ5400 2003-004, 73 Pages, 2000/02

JNC-TJ5400-2003-004.pdf:8.3MB

none

Research for the erosion of buffer material with the vertical disposal concept, 3; In situ tests on engineering scale at Horonobe URL

Ono, Makoto*; Motoshima, Takayuki*; Shirase, Mitsuyasu*; Yokoyama, Satoshi*; Jo, Mayumi*; Ishii, Tomoko*; Nakayama, Masashi; Ono, Hirokazu

no journal, , 

To understand phenomenon of buffer material erosion in the vertical disposal concept, in situ tests on engineering scale have been carried out at Horonobe URL. As results of water injection with flow rate control, when water flowed in a continuous large flow rate, buffer materials did not swell enough to stop the water flow and the water flow path was confirmed to be formed by aggregated into a single pipe. Further, it was suggested that water pressure of the injection side contributes to the erosion of buffer materials.

The In-situ experiment for verification of performance of engineered barrier system in Horonobe Underground Research Laboratory, 2; Investigation of the compaction property and permeability of backfill material using surplus soil from the URL construction

Sawada, Sumiyuki; Nakayama, Masashi; Tanai, Kenji; Morikawa, Yoshito*; Jo, Mayumi*

no journal, , 

no abstracts in English

Study on methods to prevent piping and erosion in buffer materials intended for a vertical disposal pit, at Horonobe URL

Jo, Mayumi*; Iwatani, Takafumi*; Kawakubo, Masahiro*; Ishii, Tomoko*; Ono, Makoto*; Nakayama, Masashi

no journal, , 

For the purpose of "maintaining the soundness of the artificial barrier", we are studying "restraints on the outflow of the buffer material". We conducted an experiment of a scale of 30 cm to 1 m in an actual underground environment and confirmed the occurrence of the buffer material outflow under water inflow conditions. The experiment in this study was undertaken in order to acquire the necessary data for considering a method to control the outflow of the buffer material.