超前预注浆堵水在万家寨引黄工程支(北)01洞涌水段施工中的应用

Pilot Pre -grout for Stopping Water i n Blow Section of Tunnel,Wanjiazhai YRDP(Yellow River Diversion Project)

北干线支(北)01隧洞段由于地质情况复杂,涌水量较大,采用深孔分段式超前预注浆施工,使洞内涌水得以控制,并顺利通过了该地段。

The downstream side of tunnel NO(01),lateral(the north),the north main line,Wanjiazhai YRDP surrounding rock is cataclastic dolomitic limestone,wormkalk belonging to the upper cambrian series,camb rian sys-tem,where the discharge of blow is so high,about 300cubic meters per hour ,that the measure,the pilot pre -gro uting for stopping water simply must to be t aken,As a result of taking this measu re,more than 90%of the discharge of t he blow had been reduced enabling the ex cavation passing through the blow se ction of the tunnel to be completed wi thout a hitch.That the matters introduced in this paper are briefly summarized as follows:grouting agent,cement g rout and water glass grout;grouting process,stage grouting from working face,e ach stage is less than 15meters;grou ting pressure,3.3kg /cm 2 (design value).Fig.1.and Fig.2show the layout of t he grouting holes.