Effects of Degree of Saturation on Shallow Landslides Triggered by Rainfall

• Main Authors: Hsin-Fa Chen, 陳新發
• Other Authors: Tung-Lin Tsai Ph. D.
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/46909065095864211404

碩士 === 國立嘉義大學 === 土木與水資源工程學系研究所 === 97 === The empirical rainfall threshold concept and the physically-based model are two commonly used approaches for the assessment of shallow landslide triggered by rainfall. To investigate in detail the rainfall-triggered shallow landslide, many physically-based models coupling the infinite slope stability analysis with the rainfall infiltration modeling in variably saturated soil were developed. However, in those physically-based shallow landslide models, the unit weight and the shear strength of soil were assumed constant rather than depending on the degree of saturation. This assumption could affect the assessment of shallow landslides. In this study, the influences of the unit weight and the shear strength of soil as function of degree of saturation on rainfall-triggered shallow landslide are examined. Several designed scenarios are used to conduct this examination. The results show that not only the occurrence of shallow landslide but also the failure depth and the time to failure could be misassessed if the effects of degree of saturation on the unit weight and the shear strength of soil are neglected.