白鹤滩水电站分流挡渣堤保护方案优化试验研究

Experimental Research on Optimization for Protection Scheme of Diversion Cofferdam in Baihetan Hydropower Station

为优化白鹤滩水电站分流挡渣堤的保护措施,针对分流挡渣堤过流时的冲刷问题,采用模型试验方法,在无堆渣、右岸半堆渣、全堆渣92×104 m3情况下,选取最不利流量16 500m3/s,研究了上、下游分流挡渣堤的冲刷状况。结果表明,在过流量为16 500m3/s时,河床堆渣量增多有利于挡渣堤的防护,上游挡渣堤堤顶及1∶5缓坡段受冲刷较为严重。据此提出了三种优化防护方案,模拟5年一遇典型洪水的来流过程进行对比试验,得到了最优方案,可缩短挡渣堤施工工期并节约工程投资。

In order to optimize the protection measures of diversion cofferdam in Baihetan hydropower station,model test method was used for the scouring problem when water flows through the diversion cofferdam.The most unfavorable flow of 16 500 m^3/s was selected to study the scouring results of the upstream and downstream diversion cofferdam under the conditions of three different slag volume in the riverbed.The results show that when the flow is 16 500 m^3/s,the increase of slag volume in the riverbed is beneficial to the protection of the cofferdam,the top of the upstream cofferdam and1：5 gentle slope were scoured more seriously.Therefore,three kinds of optimized protection scheme were proposed to perform a comparative test by simulating the flow of typical floods every 5 years.The optimal scheme was obtained,which can shorten the construction period of diversion cofferdam and save investment in engineering.