金沙水电站二、三期导截流施工方案分析

Analysis on construction scheme of second and third phase river diversion and closure works of Jinsha Hydropower Station

金沙水电站导截流工程具有流速大、截流落差高、施工工期紧等特点。为保证截流成功,利用水力学计算并开展模型试验,选取了预进占单戗立堵截流、截流戗堤与围堰分开布置的方法进行施工。结果表明:针对河道较宽和导流明渠狭窄、流速大的情况,预进占单戗立堵截流能有效降低截流风险和截流难度,可实现快速截流并降低投资成本。研究成果可为类似工程提供参考。

Aiming at the characteristics of diversion and closure project in Jinsha Hydropower Station,such as high flow velocity,high closure drop,and tight construction period,to ensure a successful closure,we used hydraulic calculations and model test results to select the construction method of pre-advance occupancy and vertical block⁃ing and the separation of closure levee and cofferdam.The results showed that in the case of wide river,narrow di⁃version channel and high flow rate,pre-advance occupancy and vertical blocking could effectively reduce the risk and difficulty of river closure,achieve rapid closure and reduce the investment cost.The research result could pro⁃vide reference for similar projects.