阿海水电站围堰防渗墙缺陷修补施工

Defect repair construction of cofferdam cutoff wall of A′hai Hydropower Station

阿海水电站截流采用了大量的块石和钢筋石笼,在后续上游防渗墙施工过程中,因成槽部位地层结构复杂导致卡钻且处理困难,围堰无法闭气。经研究,采用了高压旋喷灌桨技术进行了缺陷部位的防渗处理。介绍了在特珠地层条件下,高喷施工参数的选择,以及浆液的调整与组合,并对关键技术处理措施及质量控制方法进行了阐述。施工完成后,防渗墙已经过两个汛期的运行,证明防渗效果满足工程需要,为同类基础的施工积累了经验。

A large quantity of block stone and reinforced gabions were used in the river closure project of A′hai Hydropower Station.In upper cutoff wall construction,due to driller lock induced by complex geology at diagram forming stratum,the cofferdam could not be water-tightened.High pressure whirl-spray grouting was adopted for controlling seepage at defect area.We introduced the selection of parameters of high pressure whirl-spray grouting and adjustment and combination of slurry,under special formation condition;and the key technical treatment measure and quality control measure are described as well.The construction methods were proved effective by tests of two years flood seasons,which can be referred by other projects.