Based on hydraulic model tests of a reinforcement project, the water flow pattern, velocity distribution, maximum depth-averaged velocity of a typical section, and scouring characteristics downstream of the sluice were measured, and the cause of water flow pattern deterioration and scour severity under the design scheme were analyzed. The cause is considered to be the change of the flow boundary condition after reinforcement of the downstream wing wall, which concentrates the main flow downstream of the sluice, increases the velocity locally, and intensifies scouring. Through comparison of different energy dissipation and scour prevention schemes, the method of using partition piers to eliminate the flow accumulation is put forward. Partition piers can eliminate the main flow extrusion by the boundary, improve the flow pattern downstream of the sluice, homogenize the velocity distribution downstream of the sluice, reduce the maximum velocity of the river bed, and decrease scour downstream of the sluice. The partition piers have a simple structure and construction.%基于某除险加固工程水力学模型试验,通过对闸下水流流态、流速分布、特征断面垂向最大平均流速以及冲刷特性的观测,分析了设计方案条件闸下水流流态恶化及冲刷严重的原因,即下游翼墙加固改变了水流的边界条件,导致出闸水流受到边界挤压而主流集中,局部流速增大,冲刷加剧.通过不同消能防冲方案的试验比较,提出了利用分隔墩消除出闸水流集中的现象;分隔墩消除了主流受边界挤压现象,起到了改善闸下水流流态,均化闸下水流流速分布,降低河床最大流速,减轻闸下冲刷的作用,且体型结构简单,易于施工.
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