Backfilling test in the groundwater recovery experiment, 2; Effective factors on saturation of backfilling material

Ozaki, Yusuke  ; Onoe, Hironori ; Takayama, Yusuke  ; Takayasu, Kentaro; Takeuchi, Ryuji  

The purpose of this study is to identify factors that dominate the saturation in bentonite mixture material during drift closure test. The bentonite mixture buried in two pits in the test drift is monitored to evaluate its hydro-mechanical behavior during the test. To clear the factors effective to the saturation in the mixture, we perform numerical simulation focusing on the effect of swelling, hydraulic conductivity and unsaturated characteristics in the mixture. Our simulation results show that the unsaturated characteristics of the mixture have the greatest effect on the saturation in the mixture. For accurate estimation of saturation change in the mixture, unsaturated characteristics data is key information.