积石峡水电站施工导流设计概述

General Description of Design of Construction Diversion,Jishixia Hydropower Project

积石峡水电站采用土石围堰一次拦断河床、大坝基坑全年施工、左岸隧洞过流的施工导流方式。主河床截流后枯水期导流洞单独泄流,汛期导流洞与泄洪排沙底孔联合泄流。该工程施工期的洪水流量选择充分利用了河段梯级上游龙头水库龙羊峡水电站的调洪控泄作用,导流洞下游段与中孔泄洪洞结合,且汛期利用泄洪排沙底孔参与导流,减小了导流建筑物规模,节约了工程投资,取得了较好的技术经济效益。

In construction of Jishixia Hydropower Project, the river is closed by the earthrock cofferdam once and the river flow is diver ted through the diversion tunnel on left bank so that the construction activities in the foundation pit could be executed the year round. At2 ter the main riverbed is closed, the river flow in the lowwater period is discharged by the diversion tunnel individually ; in the flood sea stm, by the diversion tunnel and the bottom outlet together. During the project construction, the function of the flood control by the up stream Ltmgyangxia Hydropower Station is fully utilized to control the incoming discharge, the downstream section of the diversion tunnel combines the middle flood discharge tunnel and the bottom outlet is applied for the flood diversion in the flood season so that the scale of the diversion structure is decreased, investment is reduced and a expected technical ＆ economic benefits are gained.