南哨水电站拱坝体型设计

南哨水电站位于雷公山暴雨中心区， 洪水峰高量大， 水库基本无滞洪削峰， 由于坝址处河床深切而狭窄， 溢洪道作拱坝坝身表孔溢流短鼻坎挑流的布置。为使溢洪道既有较好的挑流消能效果， 又能达到控制大坝工程投资的双重目的， 将混凝土拱坝体型作了一反常规的设计布置， 即河床部分悬臂梁的上部向水库倒悬呈负坡， 岸边悬臂梁渐变为竖直呈正坡； 水平拱圈曲率由高到低逐渐变小， 而曲率半径则逐渐加大。拱坝的体型适应了溢洪道作高落差挑流鼻坎的布置， 使其溢洪舌远离坝脚， 经运行１３ 年来多次洪水的检验， 在下游不做消能防冲工程措施的情况下， 保证了大坝和下游两岸岩体的稳定安全， 而大坝和溢洪道运行状态良好。

Formation Design of Arch Dam for Nanshao Hydropower Station

Nanshao Hydropower Station is located at the center area of Leigongshan rainstorm,the flood peak is very high,and the reservoir has basically not the ability of storing flood and regulating the peak.The riverbed in the dam site is deep and narrow,the spillway with short bucket lip,therefore,is set on the top of the dam.In order to make the spillway economic and work well,the formation of the concrete arch dam was non-conventionally designed.It means that the cantilevers on the riverbed was designed to adverse slope,the cantilevers on the both banks become upright gradually,curvatures of level arch rings become smaller gradually from high to low while their curvature radius larger.The formation is suitable for the layout of spillway with high fall bucket lip,becaus the spilling jet is far from the dam heel.In the case that measures of dissipation and erosion control are not taken on the dam downstream,the dam successfully resisted several floods during operation period of 13 years.