下桥水电站拱坝消能防冲设计与初期运行消能效果

龙江下桥水电站拦河拱坝处在背斜轴部，河床岩石破碎，抗冲能力低，厂坝之间相距近，用此前传统单坎式水垫塘，因消能效率低，不利坝基坝肩安全，也不能为电站尾水渠提供良好水力条件。作者重点叙述“三坎式水垫塘”产生的背景、依据与效果；介绍水垫塘结构设计要点与三年来泄洪消能工初期运行情况。

Energy Dissipation & Erosion Protection Design and Preliminary Operating Effect of Arch Dam at Xiaqiao Hydropower Station

The arch dam of Xiaqiao Hydropower Station in Longjiang River is located in axial region of anticline where there are crashed rocks at the river bed. As the dam has a low erosion-resisting capacity and is adjacent to the plant, the traditional single-ridge plunge pool with a low energy dissipation efficiency can neither ensure the safety of dam foundation and abutment nor provide sound hydraulic conditions for the tailrace of the power sta- tion. The background, reference and effect of three-ridge plunge pool are presented in details together with the design gist of plunge pool structure and the preliminary operating status of flood discharging energy dissipation over the Past three vears.