纯化水库防渗方案的优化研究

Optimization study on seepage control of Chunhua reservoir

在黄河三角洲近代冲积平原上修建水库,一般蓄水深度仅4～5 m.围坝挡水水头虽低,但出现渗透破坏的工程实例并不少见.纯化水库设计蓄水深度8.5 m,防渗安全问题尤为突出.为解决渗透问题,提出2种防渗方案:一是只对坝基做垂直铺塑防渗,二是坝体铺设复合土工膜与坝基垂直铺塑联合防渗.经比较,后一方案的出逸点高度、出逸坡降和单宽渗流量均低于前一方案.这表明坝体和坝基联合防渗具有较好的防渗效果,故将这一方案确定为纯化水库的防渗方案.同时对垂直铺塑距上游坝脚的距离进行了研究.多年渗流安全监测成果表明,纯化水库防渗效果良好.

Most of the reservoirs constructed in the Yellow River Delta alluvial plain,in general,have the water depth of 4~5 meters,but the destruction of their dams by seepage is not uncommon.However,Chunhua reservoir has a design storage depth of 8.5 meters,and its impermeable security is particularly prominent.This paper presents two anti-seepage solutions： A,vertical spreading plastics in dam foundation;and B,laying composite geomembrane at upstream slope and vertical plastics combined with underlying impermeable layer,which form a closed anti-seepage system.The seepage exit height,exit gradient and discharge per unit width of B are all better than those of A.So the anti-seepage solution of B is applied to the seepage control of Chunhua reservoir dam.Meantime,the different positions of vertical spread geomembrane from the upstream dam foot are studied.The safety monitoring results of ten years show that the anti-seepage system of Chunhua reservoir is running in a good condition.