| Title |
Infiltration and Stability Analysis Using Double Modal Water Retention Curves for Unsaturated Slopes in Pohang |
| Authors |
오세붕(Oh, Seboong) ; 장준혁(Jang, Junhyuk) ; 윤석용(Yoon, Seokyong) |
| DOI |
https://doi.org/10.12652/Ksce.2024.44.5.0695 |
| Keywords |
불포화토; 침투; 비탈면; 안정해석 Unsaturated soils; Infiltration; Landslide; Stability analysis |
| Abstract |
As a result of Typhoon Hinnamnoh, several slope failures occurred in the Pohang region, it is necessary to perform infiltration and slope stability analyses due to the actual rainfall. In the failed sites, samples were collected, and the hydro-mechanical properties of unsaturated soil were examined. Modeling the actual behavior using a single-mode function characteristic curve was found to be inadequate, leading to the adoption of a dual-mode function characteristic curve. The dual-mode function showed better agreement with the water retention test data. We calculated the unsaturated hydraulic conductivity for single and dual modes and performed rainfall-induced infiltration analysis. The variations in saturation and pore water pressure were calculated due to rainfall for three landslide-prone areas, Stability analysis based on effective stress of unsaturated soil was conducted, and safety factors were computed over time steps. The dual-mode model successfully reproduced landslides triggered by Typhoon Hinnamnoh, while the single-mode model exhibited a minimum safety factor of 1.2-1.3, making slope failure unpredictable. The dual-mode model accurately predicted instability in the slope by appropriately accounting for pore water pressure variations during Typhoon. |