水库坝前及泄水底孔内泥沙淤积形态断面模型试验

Sedimentation in Front of the Dam and in the Pressure Conduit of Bottom Outlets of a Reservoir: Sectional Model Experiment

通过断面泥沙模型试验,对某水库泄水底孔压力段内泥沙淤积形态和坝前泥沙淤积高程进行了分析研究.试验结果表明,在泄水底孔关闭运用的前两个月(10月和11月)坝前泥沙淤积速率较高,这两个月的泥沙淤积厚度达25.8m,约占坝前总淤积厚度的600/0,坝前最终淤积高程为949.9m;设置在左岸坝段的引黄取水口在正常引水期间一般不会淤堵;泄水底孔压力段内泥沙淤积面随着坝前淤积面上升而抬高,当10月底坝前淤积面高程达到925.6m时,压力段内已基本堵满淤泥.所以在设计底孔闸门启门力时,泥沙压力及摩擦力可按满孔泥沙考虑.

A sectional model experiment was carried out to determine the sedimentation elevation in front of the dam and sedimentation configuration in the pressure conduits of bottom outlets of a reservoir on the Yellow River. The results show that sedimentation in front of the dam develops rapidly in the first two months during the impoundment period. Within the two months, the thickness of deposition reaches 25.8 m, about (60~0_0) of the total thickness. The sedimentation elevation finally observed in front of the dam is 949.9 m. The intakes on the left bank are usually not silted up. When sedimentation elevation in front of the dam reaches 925.6 m at the end of October, the pressure conduits of bottom outlets are entirely silted up. Therefore, when the lifting force of gate of the bottom outlets is designed, the sediment pressure and friction force should be considered by full holes sediment.