长沙综合枢纽施工导流方案优化

Optimum studies on diversion schemes for the construction of Changsha hydroproject

针对长沙综合枢纽工程各期围堰情况下束窄河道的行洪能力,对分段围堰法和淹没基坑法相结合的施工导流方式进行优化.采用1∶100的正态水工模型进行流场分析试验,合理分配原设计方案的二、三期施工导流溢流宽度,同时优化纵向围堰平面布置以减小回流区域.对泄流能力和水力特性观测结果进行分析后得出,优化方案能有效调顺束窄河道的水流方向,明显减小回流区域,增加束窄河道的有效溢流宽度;二、三期围堰水位壅高值分别降至0.28和0.43 m,泄洪能力有了较大提高.优化后的施工导流方案已经在长沙综合枢纽施工导流实践中取得了理想的行洪效果,可供同类工程参考.

When a hydroproject is being buih at the downstream reach of a city, flood control becomes a very important task. Especially during the construction diversion, the width of overflow is reduced, which leads to water rising at the upstream. If the water rising is too high, the wealth and the life by the riverside can be seriously threatened. So this article aims at the study of the construction diversion schemes for the Changsha hydroproject by using 1 .＂ 100 physical model test method. Based on the observed results of discharge capacity and waterpower characteristics, proposals on diversion＇s spillway width and the plane arrangement types of the longitudinal cofferdam are optimized so as to effectively regulate the flow in the narrowed river. Thus the effective width of the overflow is increased, and the water rising and the upstream flooded area are reduced. The optimized construction diversion scheme has a marked flood discharge effect during Changsha hydroproject construction diversion, which can be for similar hydroprojects reference in future.