Vol16 No.4: 806-820
【Title】Reactivation of a huge ancient landslide by surface water infiltration
【Author】TU Guo-xiang1; HUANG Da2*; DENG Hui1
【Addresses】1 State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu 610059, China; 2 School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China
【Corresponding author】HUANG Da
【Citation】Tu GX, Huang D, Deng H (2019) Reactivation of a huge ancient landslide by surface water infiltration. Journal of Mountain Science 16(4). https://doi.org/10.1007/s11629-018-5315-5
【Abstract】An ancient landslide, situated in Deqin County, Yunnan Province, China, was used to investigate the reactivation by water infiltration. This study considers the infiltration process and landslide stability using finite-element method (FEM)-based models. The results show that the reactivation of old landslide deposit was triggered by the long-term leakage of diversion ditch before October 2012, and the reactivation was triggered again by the intense rainfall on 7-9 October 2012. The old cracks, which formed in the earlier reactivation of landslide, played a key role for the rainfall infiltration. They offered a preferential path for much more rainfall to infiltrate fast into deep soil, and caused wetting front to move down faster in landslide. The old slip zone with lower permeability was another important factor to cause the infiltrated water to accumulate and form a high pore water pressure above slip zone. Then the high pore water pressure decreased the shear strength of slip zone and triggered the reactivation of the old landslide deposit again.
【Keywords】Landslide; Rainfall infiltration; Soil stability; Finite-element-method; Leakage of diversion ditch