Studies on engineering technologies in the Mizunami Underground Research Laboratory

Matsui, Hiroya ; Mikake, Shinichiro ; Asai, Hideaki; Sugihara, Kozo

In the construction phase of the MIU project, engineering studies have focused on research into design and construction technologies for deep underground. The main subjects consist of the following: "Demonstration of the design methodology", "Demonstration of existing and supplementary excavation methods", "Demonstration of countermeasures during excavation" and "Demonstration of safe construction". In the FY 2007, identification and evaluation of the subjects for this study were carried out to optimize future research work. Specific studies have been performed as well. Based on these studies, future research focused on the four subject areas has been identified. The design methodology in the surface-based investigation phase was verified to 200 m depth. Evaluation of countermeasures and studies of concepts for the estimation of the influence of high differential water pressures, long-term maintenance and risk management have been proposed with respect to the geological disposal project.