Transient Analysis on Infiltration and Stability for Unsaturated Soils in Busan Landslide Area

Abstract: Several areas in Busan have been recognized to experience actual failure due to heavy rainfall precipitation. Case histories are shown in Busan landslide area. The time dependent infiltration in unsaturated layers are assessed by using one-dimensional model, and the stability of the layers are calculated in the infinite slope. As a result, in the actual failure zones, the slopes become nearly or fully saturated and experience failure as the factor of safety reduces into ~1.0. It is found that the transient infiltration and stability analyses under three constitutive relations (soil water characteristic curve-hydraulic conductivity function-suction stress characteristic curve) framework can simulate the failure in the landslide area.