Investigation of the excavation disturbed zone due to the excavation of horizontal galleries; Study in the Horonobe Underground Research Laboratory

Kubota, Kenji*; Aoyagi, Kazuhei; Sugita, Yutaka

Koeki Shadan Hojin Butsuri Tansa Gakkai Dai-138-Kai (Heisei-30-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu, p.51 - 54, 2018/05

In an excavation of shafts and galleries in the deep underground for disposing high level radioactive waste, an excavation disturbed zone (EdZ) or excavation damaged zone (EDZ) is developed around the shafts and galleries owing to the stress redistribution. It is important to understand the behavior of the EdZ or EDZ because these zone could have an effect on the transfer behavior of radioactive nuclide. Therefore, the authors performed the in situ experiment to investigate the behavior of EdZ or EDZ in the 140m and 250m gallery in the Horonobe Underground Research Laboratory. From the result of the experiments, the authors compared the characteristics of EdZ or EDZ between those in 140m and 250m gallery. The extent of the fractures induced by the gallery excavation, i.e., EDZ was about 0.45m in the 140m gallery and about 1m in the 250m gallery. The extent of the unsaturated zones related with EdZ was about 1m in the 140m gallery, however, unsaturated zone was not appeared in the 250m gallery.

None

; Koide, Kaoru*; *; Yoshida, Eiichi; *; ; Fujita, Tomoo

PNC TN1410 97-038, 307 Pages, 1996/04

PNC-TN1410-97-038.pdf:14.38MB

no abstracts in English

Evaluation of mechanical and hydrological effect at the time of shaft excavation in the Horonobe Underground Research Center

Hata, Koji*; Niunoya, Sumio*; Aoyagi, Kazuhei; Fujita, Tomoo

no journal, , 

no abstracts in English

Investigation of the excavation disturbed zone due to the excavation of galleries; Study in the Horonobe Underground Research Laboratory

Kubota, Kenji*; Morifuji, Yohei*; Aoyagi, Kazuhei; Sugita, Yutaka

no journal, , 

We performed in-situ experiments such as seismic and electrical resistivity tomography, geological survey and so on before, during, and 11 years after excavation of galleries at 140 and 250 m depth in an area of soft sedimentary rock in the Horonobe Underground Research Laboratory, Hokkaido, Japan. The results demonstrate that the extent of fractures and unsaturated zone induced by the gallery excavation were clarified. The extent of fractures related with EDZ was limited in about 0.45 m from the gallery wall in the 140 m gallery and to about 1 m from the gallery wall in the 250 m gallery. The extent of the unsaturated zone related with EdZ was about 1 m in the 140 m gallery, but it was not appeared in the 250 m gallery. Such changes induced by the gallery excavation occurred within one year after gallery excavation. On the other hand, the extension of the developed fractures and unsaturated zone was hardly clarified in about 11 years after gallery excavation.

Study on sealing performance cut off excavation damaged zone with clay-based materials, 3; Evaluation of permeability based on groundwater flow analysis

Dan, Hanae*; Motoshima, Takayuki*; Kimura, Shun; Takeda, Masaki

no journal, , 

no abstracts in English