The Construction of geological model using an iterative approach; Step 1 and step 2

Matsuoka, Toshiyuki; Kumazaki, Naoki*; Saegusa, Hiromitsu; Sasaki, Keiichi; Endo, Yoshinobu*; Amano, Kenji  

One of the main goals of the Mizunami Underground Research Laboratory (MIU) Project is to establish appropriate methodologies for reliably investigating and assessing the deep subsurface. This report documents the results of geological modeling of Step1 and Step2 using the iterative investigation approach at the site-scale (several 100m to several km in area). For the Step1 model, existing information (e.g. literature), and results from geological mapping and reflection seismic survey were used. For the Step2 model, additional information obtained from the geological investigation using existing borehole and the shallow borehole investigation were incorporated. As a result of this study, geological elements that should be represented in the model were defined, and several major faults with trends of NNW, EW and NE trend were identified (or inferred) in the vicinity of the MIU-site.