三峡水利枢纽上下游引航道冲沙措施研究

借鉴葛洲坝工程的成功经验,有必要采用“动水冲沙“的方法解决三峡枢纽运行至中后期上、下游引航道中的泥沙淤积量较大的问题。为论证冲沙设施布置合理与否及不同大小冲沙流量的冲沙效果等,在完成地下电厂方案的长系列水文年(31 2a至70 6a)淤积试验后对各种年型及冲沙引用流量进行了冲沙试验。冲沙试验成果表明:上下游引航道冲沙效果随冲沙流量增大而增大,下游水位降低对提高冲沙效果有一定成效,上下游引航道水流条件不同,冲沙效果下游往往受上游影响,根据非平衡输沙原理,同一冲沙流量条件下,上游冲沙量较大时,下游冲沙量会有所减少。

Research of sand sluicing measure in the upstream and downstream approach channel of the Three Gorges hydraulic project

In reference to the successful experience of the Ge Zhouba project,there is a need to adopt the new method-"dynamic flushing"-to solve the problem of sediment deposition in the upstream and downstream approach channel in the Three Gorges hydraulic project when it works to the mid or last course.To demonstrate whether the arrangement of flushing establishment is reasonable and the flushing effect of different flushing flow rate and so on,the flushing experiment was made.This was made before completing the sediment experiment which of long series of hydrological years(31 2 years to 70 6 years) in underground electric power plant.The results illustrated that the flushing effect of the upstream and downstream approach channel will increase with the flow rate,and the level fall of downstream will have some benefit for the increasing of flushing effect, and the river condition of approach channel in the upstream and downstream is different,and the flushing result of downstream is effected by the upstream,and at the same condition of flushing flow rate,when sluicing capacity in the upstream increases,it will decrease in the downstream by the principle of the non-balance sediment discharge.