顶部设置橡胶坝的复合型溢流堰试验研究

Research on a kind of composite overflow weir with a rubber dam on the top

结合实际工程,对某顶部设置橡胶坝的复合型溢流堰进行了体型优化及过流能力两个方面的试验研究。模型试验表明:原设计方案的堰面存在大面积负压,不利于大坝安全运行,需要对复合堰的体型进行优化。另一方面,该复合堰由于堰顶设置了平台及橡胶坝袋的影响,其过流能力略低于一般实用堰。经多组修改方案试验比较,最终采用堰顶平台设凹槽、平台下游为幂曲线的复合型剖面。修改后的堰型有效减少了堰面负压区面积,改善了流态,并获得相对较高的流量系数。通过试验给出的复合型实用堰剖面形式及流量系数值为工程设计提供了可靠的依据。

This paper studied on the configuration optimization and discharge capacity of a kind of composite overflow weir with a rubber dam on the top in practical projects. The hydraulic experiment show that there is a large negative-pressure area on the weir surface in the old project which has bad effects on the stable operation of the overflow dam, so the configuration optimization is necessary. In addition, the effects of the platform and the rubber dam on the top of the weir makes it has a smaller discharge capacity than that of the ordinary practical weir. Afer comparing many modified projects, the modified design finally adopts a kind of composite weir with a power curved surface in the downstream and a concave trough on the top. The modified weir not only improves the bad condition of the flow, but also gains a relative large flow coefficient. Through the hydraulic model, we provide the flow coefficient of this composite overflow weir and reliable model for the designing of this kind of weir.