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该文建立了洪水漫堤导致河堤溃决的平面二维水沙运动数值模型,以模拟溃口扩展和堤身冲刷的过程。该模型基于有限体积法、采用显式格式求解平面二维水流运动和非平衡全沙泥沙输移方程,并考虑了边坡崩塌、底床急剧变形以及高浓度泥沙输移对水流运动的影响。溃口处的混合流场采用HLL approxim ate Riemann solver处理,非黏性土溃口边坡的崩塌采用不同干、湿静止角处理。通过对英国HR Wallingford实验室一组实验的计算,结果表明该模型能较好地模拟非黏性土堤坝溃决过程中的溃口展宽、坝体冲刷、流场分布以及溃口流量过程线。对模型参数的敏感性分析显示了水沙耦合溃决模型的非线性特征。
In this paper, a two-dimensional numerical model of runoff and sediment movement caused by embankment collapse in flood embankment is established to simulate the process of collapse and embankment erosion. Based on the finite volume method, the model is used to solve the planar two-dimensional flow motion and the non-equilibrium sediment transport equation in an explicit format. The model considers the effects of slope collapse, drastic bed deformation and high-concentration sediment transport on water flow influences. The mixed flow field at the breach mouth is treated by the HLL approxim ate Riemann solver, and the collapse of the non-clayey culvert slope is treated with different dry and wet static angles. The results of a set of experiments in HR Wallingford Laboratory in the UK show that the model can well simulate the process of collapse, erosion, flow field distribution and the process flow of unloading clay in the process of collapse of non-clay dam. The sensitivity analysis of the model parameters shows the nonlinear characteristics of the water-sand coupling failure model.