灌浆可以防止引黄工程土洞的渗漏

防止引黄工程土洞的渗漏是个重要问题。南干３＃隧洞的灌浆情况说明，实实在在地搞好灌浆足可以防止渗漏。

The Seepage of Earth Tunnel in the YRDP May Be Prevented with Grouting

The seepage prevention of earth tunnel is an important problem for the YRDP,however,that the seepage can be fairly prevented if the backfill grouting is done well has been illustrated by the fact of grouting practice of No.3 tunnel in the South Lain Line.The overall length of the tunnel No.3 is 6163.698m,of which the earth tunnel is 860 meters long,being the longest earth tunnel in the YRDP.Of the earth tunnel,the longitudinal slope is 1/1500,the cross section is horseshoe type,the design water level in the tunnel is 3.08m,the maximum discharge is 25.8m 3/s.The earth tunnel passes mainly through overburden of soils,in which N 2,the red soil,the pliocene,Q 2,the lower surface of the old loess,the meso-pleistocene,and Q 3,the upper surface of the old loess, the epipleistocene are included.Many a time has the earth collapse occurred.The double layers support has been adopted.The earth tunnel excavation was started in October,1995,and the lining was finished in May,1998.The backfill grouting was started in Summer,1998,it is expected to be completed by the end of the same year.Some suggestions are finally given in this paper.