基于二维水动力模型的溃坝洪水数值模拟研究

Numerical Simulation on Influence of Dam-break Flood Based on Two-dimensional Hydrodynamic Model

【目的】研究水库溃坝洪水影响。【方法】以辛庄水库为例,通过建立二维水动力模型,模拟了不同溃决方案下溃坝洪水演进过程,计算了下游高速铁路处淹没水深、流速、冲刷深度等,分析了溃坝洪水对下游高速铁路的安全运行影响。【结果】水库未溃决时,溢洪道最大下泄洪水能够正常通过铁路涵洞,对下游工程影响较小;水库大坝正面溃决的影响要比侧面溃决的影响大,下游部分铁路路基顶面过水,影响铁路正常运行;大坝溃决后最大流速是未溃决时的2.15~2.48倍,涵洞处最大冲刷深度是未溃决时的1.56倍。【结论】二维水动力模型可较好的模拟溃坝洪水演进过程和淹没范围,研究成果可为水库溃坝洪水灾害预防提供参考和数据支撑。

【Objective】The purpose of the paper is to study the effect of dam-break flood.【Method】Taking Xinzhuang reservoir as an example,a two-dimensional hydrodynamic model was established to simulate the evolution process of dam-break flood under different schemes,and the water depth,velocity and erosion depth of downstream high-speed railway were calculated,so as to analyze the impact of dam-break flood on the safe operation of downstream high-speed railway.【Result】The results showed that the maximum discharge flood of the spillway could pass through the railway culvert normally when the reservoir was not breached,and it had little impact on downstream project.The impact of dam break on the front was greater than that on the side,the top surface of partial railway embankment overflowed and affected the normal operation of railway.Compared with the normal condition,the maximum flow velocity was 2.15~2.48 times and the maximum scouring depth at the culvert is 1.56 times.【Conclusion】The two-dimensional hydrodynamic model can be used to simulate the evolution process and submerged area of dam-break flood,and the research results can provide reference and data support for the prevention of dam-break flood.