蔺河口水库坝顶表孔泄洪消能布置试验研究

Experimental research on crest spillway flood energy dissipation for the Ninghekou dam

蔺河口水库大坝为碾压混凝土双曲拱坝 ,最大坝高 10 0 m,主要由设在坝顶中央的 5个表孔溢洪道泄洪。通过 1∶ 80的水工整体模型对其泄洪消能布置进行了比较深入的试验研究 ,利用一种独特的布置方式和一种能使水流产生三维扩散的新型消能工实现了高低坎水流碰撞消能、横向扩散碰撞消能 ,以及最大限度地增加落水面积 ;充分利用下游河道水体消能 ;从而较好地解决了消能冲刷问题 ,使冲刷深度由原来的 4 0 m左右减至 15 m以下。该试验提出的布置方式和消能工可供类似工程参考。

The Ninghekou dam is a RCC double curvature arch dam 100 m in max height and a 5-bay spillway is provided at the central crest for flood releasing. The flood releasing energy dissipation facility is studied on a 1:80 hydraulic model. An unique arrangement and a new type dissipater, which can produce 3-D diffusion flows, are adopted to bring about energy dissipation by impact of low and high sill flows and impact of lateral diffusion. In addition, by increasing the falling area as large as possible and making full use of the downstream water, the problem of scouring and energy dissipation is tackled. The scouring depth is reduced from the original 40 m to less than 15 m. The arrangement and dissipater proposed in the model test may provide reference for the similar projects.