一种模拟沥青混凝土心墙坝漫顶溃决的水沙耦合数学模型

A Coupled Mathematical Model of Overtopping-induced Break of Asphalt Concrete Core Dam

为模拟沥青混凝土心墙坝漫顶溃决过程,建立了沥青混凝土心墙坝漫顶溃决水沙耦合数学模型,其中水动力学模型为固液两相湍流方程,考虑了泥沙运移与床面变形对水流运动的影响;自由面重构采用PLICVOF法使其精确重构自由表面;固壁边界使用基于离散力的浸入边界法模拟,能够更加准确地模拟含有刚体的流体运动;心墙的滑移破坏则通过力矩法进行判断。经室内水槽试验检验,模型能够较为细致地描述水流结构、泥沙运动、床面变形及心墙破坏四者之间的关系,预测的溃口流量过程与实测值也较为吻合,能够为进一步深入研究沥青混凝土心墙坝漫顶溃坝机理提供一种可选工具。

This study has established a coupled model to simulate the break process of asphalt concrete core dam.The hydrodynamic model is a solid-liquid two-phase turbulence equation.The influence of sediment transport and bed surface deformation on water movement is taken into consideration.The PLIC-VOF method is used to reconstruct free surface.The solid wall boundary is simulated using the immersion boundary method based on dispersive force.The sliding failure of the core wall is judged by the moment method.The indoor flume experiment verifies the model,proving that the model can simulate meticulously and accurately the interaction among water flow,sediment transport,bed deformation and core wall break.The predicted flow rate of the breach is also in good agreement with the measured value.The study can serve as a useful tool for further research on the mechanism of overtopping failure of asphalt concrete core dams.