淤地坝淤积对漫顶溃坝洪水影响数值模拟研究

为分析淤地坝淤积高度对漫顶溃坝洪水的影响,选择理想沟道和某小流域内的淤地坝为研究对象,采用耦合溃口演变过程的水动力数值模型,模拟分析了不同淤积程度下淤地坝溃坝洪水过程。研究表明:溃坝洪水流量随淤积高度的增加而减小,且洪峰流量与淤积高度的关系可用二次多项式拟合,相关系数均在0. 99左右,拟合精度较高;淤积高度至坝高20%和40%时,洪峰流量削减率分别达40. 50%和68. 71%,可见在淤地坝运行初期和中期,淤积对洪峰流量的削减效果显著。研究成果对淤地坝系规划及安全度汛有指导意义。

Numerical simulation on influence of check dam deposition on overtopping dam breaking flood

In order to analyze the influence of siltation height of check dam on overtopping Dam Breaking Flood, this work applies a hydrodynamic numerical model on a rectangular ideal channel and a realistic catchment to simulate the flow process of dam-break flood with different sediment thicknesses of check dam. The results showed that the flow of dam break decreases with the increase of siltation heights, and the relation between flood peak flow rate and silt thickness can be fitted by quadratic polynomial, with high fitting accuracy as correlation coefficient is around 0.99. When the sedimentation thickness reaches 20% or 40% of the dam height, the peak discharge reduction rate has reached 40.50% or 68.71%, respectively. Therefore, the reduction effect of siltation on peak flow is remarkable in the early and middle stages of siltation. Our results have guiding significance for the planning check dam system and the safety during flood season.