引水式水电站尾水出口挡沙坎结构形式设计研究和应用

Structure Design Research of Sand-guide Sill in Tailrace Tunnel Outlet of Diversion-type Hydropower Station and Its Application

为适应现场施工条件及施工工期要求,锦屏二级水电站利用原有施工围堰改建成尾水隧洞出口的挡沙坎。经研究论证表明,改建后的挡沙坎结构形式合理,而且对尾水出流流态和发电效益影响不大。新的设计结构形式降低了施工难度,改善了检修条件,缩短了施工工期,实现了设计目标,达到了预期效果,可为类似引水式电站尾水出口工程建设提供参考。

In order to meet the requirements on site construction conditions and construction period, a new sand-guide sill structure in tailrace outlet, that is transformed from cofferdam, is used in Jinping II Hydropower Station. The research shows that the new structure is reasonable, and has little effect on tail water discharge flow and power generation efficiency. The new sand-guide sill structure can reduce construction difficulty, improve maintenance condition, shorten construction period and achieve design goals. The practice provides a reference for the construction of tailrace project in similar diversion-type power stations.