柴坪水电站溢流坝下游河床冲刷试验

柴坪水电站坝址距离河床弯道较近，地质条件相对较差，大坝采用的消能方式为面流消能，使得水电站下泄水流流态比较复杂，下游河床冲刷剧烈，因此需要对水电站进行整体水工模型试验，证明水电站设计能够满足工程运行要求。研究发现溢流坝下泄水流的主流偏向右岸，对水电站下游右岸河床产生严重冲刷，对大坝的稳定性与工程安全运行造成影响，需要对水电站体型进行优化。研究采用在水电站右导墙处增加贴角，延长溢流坝左边孔左闸墩，同时去掉溢流坝左侧导墙的方式，迫使溢流坝下泄水流主流偏向河道中间。优化方案使下游河床冲刷减弱，降低了河床冲刷对大坝整体稳定性的影响，满足水电站工程运行要求，可以为类似工程提供设计参考。 The dam of Chaiping Hydropower Station is located close to the riverbed curve and has relatively poor geological conditions.The energy dissipation mode for the dam is surface flow energy dissipation,which complicates the discharge flow state of the hydropower station.The downstream riverbed suffers from violent erosion.Therefore,it is necessary to carry out overall hydraulic model test of the hydropower station to prove that the hydropower station design can meet the engineering operation requirements.This study found that the main stream of the discharge flow from the spillway dam is biased to the right bank,and has seriously eroded the riverbed on the right bank downstream the hydropower station.This affects the stability of the dam and the safe operation of the project.It is necessary to optimize the shape of the hydropower station.In this study,we increased the angle of the right guide wall of the hydropower station,extended the left pier of the left side of the spillway dam,and removed the left guide wall of the overflow dam,so as to force the main stream of the discharge flow to the middle of the channel.The optimization scheme can abate the erosion of the downstream riverbed,reduce the impact of riverbed erosion on the overall stability of the dam,meet the operational requirements of the hydropower project,and provide design reference for similar projects. 陕西省水利厅科技计划项目（2017slkj-17）；陕西省自然科学基础研究计划（2015JM5201）