Stability analysis of landslide dam with high permeability region: A case study of Hongshihe landslide dam
Journal
Shuili Xuebao/Journal of Hydraulic Engineering
Journal Volume
46
Journal Issue
10
Pages
1162-1171
Date Issued
2015
Author(s)
Abstract
Landslide dams, which often formed by quick deposits of landslide materials, are lack of sufficient consolidation, and loose in dam structure and material composition. Especially, the soil and rock materials are highly heterogeneous, comprising high permeable regions with large particles. The presence of high permeable regions may lead to internal erosion or even piping failure under high water pressure. Taking the Hongshihe landslide dam triggered by the Wenchuan earthquake as an example, the paper provides a method to analyze the stability of landslide dams under seepage by considering the influence of high permeable regions. The instability of a landslide dam under seepage is defined as a circulatory process of internal erosion and slope failure. The critical conditions of internal erosion and slope failure are identified within this method. From the seepage stability analysis of the Hongshiyan landslide dam with the present method, it is found that the presence of highly permeable region does harm to seepage stability of landslide dams. The seepage stability becomes worse with longer high permeability region, higher permeability, and smaller distance to the dam downstream toe. The Hongshiyan landslide dam with high permeable regions is likely to occur internal erosion, but piping failure is not likely due to large dam width and gentle downstream slope. Piping failure occur when the dam crest width is shorter and downstream slope gradient is larger.
Type
journal article