Numerical estimation of hydrogeological characteristics based on data from cross-hole hydraulic tests

Onoe, Hironori ; Saegusa, Hiromitsu; Oyama, Takuya ; Takeuchi, Shinji

In order to understand three dimensional groundwater flow condition in deep underground where discrete fracture are distributed, it is essential to construct hydrogeological model and to carried out groundwater flow simulations, which are based on the results of field investigations. In this study, hydrogeological model using hydraulic responses of cross-hole hydraulic tests, which were carried out in the Mizunami Underground Research Laboratory (MIU) project, was calibrated in order to estimate hydrogeological characteristics of the structure having influences on groundwater flow conditions in deep underground. As a result of the study, faults with low permeability and major water-conducting features in and around MIU Construction site were characterized. It could be also confirmed that groundwater flow simulations using data with transient fluctuation is quite useful for hydrogeological characterization in the deep underground.