earticle

영어

Rainfall is a major external factor contributing to landslides. The development of a wetting front due to rainfall increases the self-weight of the soil mass and reduces the negative pore water pressure, ultimately leading to a decrease in shear strength along the slope. Therefore, accurately estimating the depth and amount of infiltration associated with rainfall is crucial for predicting landslides. Although numerous studies have been conducted to predict the movement of the wetting front and the corresponding changes in soil water content during rainfall infiltration, many of these studies assume vertical piston flow, which leads to discrepancies from actual field behavior. In reality, a transition zone exists within the wetting front, and infiltration progresses in an unsaturated state without complete saturation. In this study, it was confirmed that the transition zone within the wetting front follows a Sigmoid-shaped profile. Based on this observation, a rainfall infiltration model was developed that incorporates both unsaturated conditions and the transitional behavior of the wetting front. The proposed model was applied to infinite slope analysis under unsaturated conditions, and its results were compared with those from conventional theoretical approaches. As a result, the proposed model demonstrated improved accuracy in predicting the wetting front and effectively captured the unsaturated and transitional characteristics of the infiltration process. Furthermore, compared to existing models, the safety factor of slopes was found to be relatively higher, with a gradual variation in safety factor observed due to the influence of the transition zone.