Study for effectiveness of rock mechanical model estimated from pilot boring survey

Niunoya, Sumio*; Matsui, Hiroya ; Mikake, Shinichiro ; Sato, Shin*; Noda, Masaru*; Hata, Koji*

In the Mizunami URL of Japan Atomic Energy Agency (JAEA), the study on engineering technology are on going. In this study, we tried to estimate the static elastic modulus from RMR (Rock Mass Rating) based on the results of laboratory test, core observation of the pilot borehole and geological survey on the shaft wall of main shaft in the URL. The static elastic modulus based on PS logging in a borehole as well. Then, the three dimensional numerical analysis using of these parameters carried out for the validity of the examination. The results show that the RMR may be applicable to estimate the mechanical parameters of strongly weathered rock mass which is widely distributed in Japan.