大岗山水电站复杂地层灌浆效果分析

Analysis on grouting effect in complicated strata of Dagangshan Hydropower Station

在大岗山水电站拱坝940 m高程以下帷幕灌浆施工过程中,出现了严重的回浆返浓现象,孔口涌水较为普遍。针对坝基陡倾节理、裂隙的特点,先后采用普通水泥、细水泥和化学浆液进行了一系列灌浆试验研究,最终确定了一套对特殊地层较为有效的灌浆工艺参数和方法。灌后检测结果表明:普通水泥和细水泥灌浆虽都能提高透水率达标率,但尚不能完全满足设计要求,而化学灌浆处理能全部满足设计要求。

In the dam curtain grouting under the elevation of 940 m in Dagangshan Hydropower Station,severe dense slurry returning occurred,and water gushing was serious generally near the grouting holes. In view of the steep joint and fissures,common cement,fine cement and chemical slurry were respectively used in the grouting process,a series of tests were conducted.Based on the grouting result of common cement and fine cement obtained by the tests,the grouting parameters and technology effective to the special strata were determined. The check result after grouting showed that grouting by common cement and fine cement could improve the up-to-standard rate of permeability,but could not fully meet the design requirement; chemical grouting could fully meet the design requirement. By the analysis on grouting parameters and effectiveness in different grouting stages,some experiences and suggestions are obtained,which can be referred by similar projects.