乐昌峡水利枢纽工程坝址处河道狭窄，溢流坝的泄洪落差和单宽流量较大，且电站尾水出水口靠近溢流坝，因此，溢流坝泄洪安全是枢纽工程的关键技术问题。通过溢流坝泄洪消能模型试验研究，对溢流坝堰面曲线、两侧收缩边墙、闸墩、挑流鼻坎等布置和体型进行了优化，改善了其运行水力特性，妥善解决了溢流坝泄洪消能防冲的问题。

This paper studies the floodreleasing and energy dissipation of the overflow dam at Lechangxia water control project which is located in a narrow river valley. The floodreleasing safety of the overflow dam therefore is a critical technical issue as it has large water head drop and the discharge per unit width of the dam is large, and moreover, the tailrace exit of the hydropower station is in the vicinity of the dam. Based on hydraulic model tests, the hydraulic property of the overflow dam is improved and hence problems of floodreleasing and energy dissipation and scour protection are solved in this paper by optimizing the layout and configuration of overflow weir and both the contracted sidewalls as well as piers and flip buckets.