Process Analysis and Prediction of a Multi-stage Landslide Dam Failure

Abstract

The studies of mechanism and calculated model of the earth-fill dam and landslide dam have a significant impact on the prediction and risk assessment for dam failure. The present study selected the event of a multi-stage landslide dam failure in southwestern China as a case study. Based on a mathematic model that can consider the failure mechanism, the key parameter can be obtained by back analysis, the twice failure processes can be displayed as well. It indicates that the second landslide dam cannot break under natural conditions, i.e. the landslide dam failure needs manual intervention, which is consistent with the actual situation. Because the landslide would occur again in different cumulated volumes in the future, the dam failure is predicted using the same model. The result illustrates that the maximal flow comes up to 20,000-60,000 m3/s after the dam failure and the failure would occur in a short day. The analysis and prediction provide an improved insight into the landslide dam failure process and risk control.