泸定水电站防渗墙下深厚覆盖层帷幕灌浆施工技术

泸定水电站坝址主河床段长100.54 m,采用悬挂式防渗墙,最大墙深110 m。墙下接覆盖层帷幕灌浆,帷幕灌浆孔入岩深度10 m,最大单孔深度达154.8 m。防渗墙下覆盖层层次结构复杂,渗透性强,成孔率低,灌浆效果难以保证。从钻孔控制、浆液成分及配比、灌浆压力的选择、灌浆结束标准、灌浆质量检查等方面对覆盖层帷幕灌浆施工进行了分析总结。

Curtain Grouting for Deep Overburden under the Cut-off Wall of Luding Hydropower Station

The section of Luding Dam on main river bed is 100.54 m length and the suspended cut-off wall with a maximum depth of 110 m is used to control seepage.The curtain grouting in overburden under the cut-off is conducted,in which,the curtain grouting holes penetrate into the bedrock about 10 m and the maximum hole depth is 154.8 m.As the complex structure and strong permeability of overburden,the pore-forming rate is low and the grouting effect is difficult to guarantee.The curtain grouting are summarized herein from drilling control,slurry composition and mix ratio,grouting pressure selection,grouting completion standard and quality inspection.