Long-term groundwater pressure monitoring in Mizunami Underground Research Laboratory Project (Phase II); Hydraulic pressure response due to the construction of Underground Research Laboratory

Karino, Tomoyuki; Tsuyuguchi, Koji; Onoe, Hironori ; Takeuchi, Ryuji  

Japan Atomic Energy Agency (JAEA) has been conducting Mizunami Underground Research Laboratory (MIU) Project. The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of 20 years. Currently, the project is being carried out under the Phase II. One of the Phase II goals is set to develop and revise models of the geological environment using the investigation results obtained during excavation, and determine and assess the changes in the geological environment in response to excavation. The long term hydro-pressure monitoring has been continued to achieve the Phase II goals. In this paper, a part of the result of long-term hydro-pressure monitoring during the URL excavation in Phase 2 of MIU project were introduced.