瑞浪超深地層研究所の再冠水試験に関わる調査研究,1; 地下坑道の冠水に伴う地下水の水圧変化

Study on groundwater recovery experiment in Mizunami Underground Research Laboratory, 1; Groundwater pressure change in the water recovery process of the underground gallery

高安 健太郎; 毛屋 博道; 尾上 博則 ; 竹内 竜史  

Takayasu, Kentaro; Keya, Hiromichi; Onoe, Hironori; Takeuchi, Ryuji

瑞浪超深地層研究所では、大規模地下施設の建設・操業により乱された岩盤中の地質環境の回復能力の例示と地質環境の回復に関わる観測・評価技術の開発を目的として、深度500mの坑道の一部を地下水で満たす再冠水試験を実施している。坑道内及び周辺岩盤中に水圧観測装置を配置し、当試験に伴う地下水の水圧変化を観測した。また、観測した水圧変化データを、デリバティブプロットとして整理しその形状に着目することで、坑道内と周辺岩盤の各観測区間における水圧変化の類似性を検討した。

The reflood test which fills the part of the tunnel of depth 500m with groundwater is being put into effect for the purpose of exemplification of the recovery ability of the geological environment in the bedrock which was disturbed by construction and operation of large-scale underground facilities, and development of observation and evaluation technique of geological environment recovery at The Mizunami Underground Research Laboratory (MIU). Water pressure observation devices were installed in the tunnel and in each observation section in the surrounding bedrock, and groundwater pressure change in this test was observed. Similarity of water pressure change between the tunnel and each observation section was considered by arranging observed water pressure change data as derivative plots and focusing their shapes.