五强溪水电站施工导流设计

Design of River Diversion During Construction of Wuqiangxi Hydropewer Station

五强溪水电站根据枯水期基坑不过水，洪水期只过水一次，不多于二次的原则，选定一期围堰挡水流量１６０００ｍ３／ｓ，二期挡水１８０００ｍ３／ｓ。经比达采用两期导流方案，主体工程工期６年。导流设计中还注意了导流底孔的开孔型式和布置，处理好一、二期围堰施工和通航建筑物布置的关系等。经汛期洪水的考验，围堰和导流底孔运行正常。

According to the principle that no water crossed the foundation pit in dry seasons, while water crossed it only once or no more than twice in find seasons, the first-stege cofferdam was designed to hold a flow discharge of 16000m3/s, and the second-stage cofferdam was designed tO hold 18000m3/s discharge.This two-staged diversion scheme was seleCted by comparison Of all alternatives. Construction of main structures was scheduled for six years. When designing the river diversion, attention was also paid to the type of bottom outlets and their layout ; and to relations between construction of the first-stage and the second-stage cofferdams and the layout of navigation structures, etc. The cofferdams and diversion bottom outlets experienced flood tests and still kept normal operation.