洪水巨大的冲击力对坝区及堤岸构筑物造成很大的破坏,准确计算溃坝洪水对构筑物的冲击荷载对于建筑物的安全设计是十分必要的。采用有限体积法和中心迎风格式建立了二维数值模型,用于计算溃坝洪水对构筑物的作用力,并将该模型应用于全局溃坝和局部溃坝的物理模型试验。计算结果表明:该模型能够准确地模拟全局溃坝工况下洪水对构筑物冲击荷载的变化情况,而对于局部溃坝工况,本模型的计算结果较为平滑,无法模拟实际水流紊动的过程,但其最大冲击荷载的计算值与试验测量值相接近。相比于三维数值模型,本文所建立的二维数值模型程序简单、计算效率高、计算结果与实测结果总体吻合较好,能够有效地用于预测溃坝洪水对构筑物的冲击荷载。
Flood disasters occurred frequently in China and caused enormous damages to buildings and infrastructures due to its large impact forces. It is necessary to calculate the impact force accurately for the safety design of buildings. In this paper, a 2D numerical model based on finite volume method and central-upwind scheme is developed to calculate the impact force on structures due to dam-break flood. The model is also employed to simulate laboratory experiments of dam break flow and partial dam break flow, respectively. Simulation results demonstrate that the proposed 2D model is able to calculate the impact force of dam break flow on structures accurately. However, for partial dam break flow, the calculated result of impact force is somewhat smooth as the present model could not simulate the process of actual flow turbulence, yet with the peak impact force close to physical experiment results. Compared with 3D models, the present 2D model is simple and highly efficient with the simulation result according well with measured result.
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