修建在深厚覆盖层上的土石围堰防渗体系设计

猴子岩水电站土石围堰建于深约80 m的深厚覆盖层上,承担着施工期间深基坑内大坝填筑的防渗任务,是整个工程成败的关键。通过地勘资料分析、数值计算成果及多方案论证,最终确定围堰河床部位的防渗采用塑性混凝土防渗墙,岸坡部位采用混凝土趾板＋固结、帷幕灌浆,堰体采用复合土工膜防渗,两岸山体通过灌浆平洞进行帷幕灌浆的防渗体系设计方案。

Study on Seepage Control System for Earth and Rockfill Cofferdam on Deep Overburden

The earth and rockfill cofferdam at Houziyan hydropower was built on a depth of about 80 meters of deep overburden layer,undertaking the seepage control task for deep foundation pit dam placement during the construction,which was key to success of the whole project.Through geological exploration data analyses,numerical computation results and demonstration programs,a seepage control system design proposal was ultimately determined,with plastic concrete diaphragm wall in the cofferdam riverbed section,concrete plinth and consolidation and curtain grouting in bank slopes,composite geomembrane in the cofferdam and the grouting adit for curtain grouting in the mountain massif of both sides.