Numerical simulation of non-cohesive homogeneous dam breaching due to overtopping considering the seepage effect
Yanlong Li, Anke Chen, Lifeng Wen, Peng Bu, Kangping Li
Abstract
The critical velocity of soil particle reduces under the influence of seepage effect, thereby affecting the dam breaching process of non-cohesive homogeneous dam. In this paper, the formula of the critical velocity considering the seepage force was deduced by analysing the soil particles force on the slope. A dam breach model of the non-cohesive homogeneous dam was established to study the effect of seepage on the dam breach process, and the corresponding calculation procedure was compiled. This paper selected Tangjiashan landslide dam as test case and simulate the dam breach process by used the model proposed in this paper. The results show that the calculated values considering the seepage effect including breach discharge, breach width and reservoir water level, etc. were in good agreement with the measured data. Thereby verified that the model can reasonably simulate the dam breach process of non-cohesive homogeneous dam so that can be used in calculation of dam breach of this type of dam and suggesting that the seepage effect can aggravate the dam failure process of non-cohesive homogeneous dams, making the peak discharge larger, the occurrence time of the peak discharge earlier, the breach wider, and the failure duration shorter, etc.