为了探讨水流流经泄水建筑物末端的窄缝挑坎时产生的水翅导致强降雨对下游造成的不利影响,进行了系列模型试验研究,分析了能够表征水翅危害强度的各参数(水翅影响区距挑坎出口位置、降雨强度等值线包裹范围面积、椭圆形态系数、椭圆偏态系数),并构建水翅危害强度表达式。利用此表达式对模型试验实测降雨强度计算分析,结果表明:来流弗劳德数增大及挑坎底板采用的俯角角度减小时,窄缝水翅对泄水建筑物产生的危害强度呈降低趋势,而对下游岸坡和环境危害强度呈增加趋势;挑坎收缩比减小时,对泄水建筑物及下游岸坡和环境的危害强度均呈增加趋势。研究成果可用于物理模型试验研究时定量评判窄缝挑坎水翅危害强度,为窄缝挑坎体型参数选择提供理论支撑。

The aim of this research is to investigate the adverse impact of heavy rainfall caused by water wing of slit-type bucket at the end of spillway. Parameters which could reflect the hazard degree of water wing are analyzed via model test. These parameters include the distance from water-wing-affected area to bucket outlet, the area enveloped by rainfall intensity contours, the elliptic shape coefficient, and the elliptic skewness coefficient. An expression of hazard intensity of water wing is also established to calculate and examine the measured rainfall intensity in the model test. Results findings suggest that when the Froude number of incoming flow increases and the angle of bottom plate decreases, the damage degree of water wing to spillway decays but to the downstream areas intensifies; when the contraction ratio of the slit-type bucket decreases, the damage degree of water wing to both the spillway and the downstream area intensifies. The research findings can be used to quantitatively evaluate the hazard intensity of water wing in physical model test and provide theoretical support for the selection of bucket shape parameters.