摘要
贵州省格八水库为浆砌石单曲拱坝,坝顶溢洪道目前存在着泄洪能力不足、表孔溢流水舌不稳定、泄洪时坝体振动明显等问题,除险加固时进行了坝顶溢流堰改造,拆除重建溢流堰体,并在下游面加厚大坝,抬高校核洪水位,增加泄洪能力。针对拱坝宜采用最“瘦”溢流堰的特点,通过试验对WES型、长研I型、克-奥型等3种曲线型实用堰的特点进行了研究和比较,最终选择了体型最瘦、便于施工放样的WES堰型。溢流堰改造后堰面水舌负压可满足规范要求,消除了水舌脱离坝面的问题,泄洪时再未发现坝体振动。同时,为解决坝下游发电厂房的雾化影响和防洪标准问题,通过水工模型试验选择了负挑角的挑流鼻坎和河床护坦+消力墩的消能工设计,较好地解决了雾化影响、水舌冲刷和发电厂房防洪问题。相关经验可供类似工程改造设计参考。
Geba Reservoir in Guizhou Province is a masonry single curvature arch dam. At present, there are some problems in the dam top spillway, such as insufficient flood discharge capacity, unstable overflow tongue in the surface outlet, obvious vibration of the dam body during flood discharge, etc. In the course of danger removal and reinforcement of the reservoir, the overflow weir body has been rebuilt, and the downstream dam surface has been thickened to lift the check flood water level and increase the flood discharge capacity. It is believed that thinner overflow weir should be adopted in arch dam, so three kinds of curved practical weir, such as WES type, Changyan I type and CO type, were studied and compared through experiments. Finally, the WES type weir was selected, which is the thinnest and is convenient for construction lofting. After the rebuilt of the overflow weir, the negative pressure of the water tongue on the weir surface was eliminated by eliminating water tongue detaching from the dam surface, and no vibration of the dam body was found during flood discharge. At the same time, in order to meet the atomization influence and flood control standard at downstream of the dam, the following joint energy dissipation schemes were selected: flip bucket with negative angle, riverbed apron and baffle block, which solved the problems of atomization, water tongue scouring and flood control of power plant.
作者
周仕刚
ZHOU Shigang(Guizhou Survey/Design and Research Institute for Water Resource and Hydropower, Guiyang 550002, China)
出处
《人民长江》
北大核心
2019年第10期162-166,192,共6页
Yangtze River
关键词
溢流堰改造
WES实用堰
消力墩
雾化影响
格八水库
overflow weir reconstruction
WES practical weir
baffle block
atomization influence
Geba Reservoir
