Research on the Application of Backwall Grouting in Leakage Treatment of Operating Tunnels

Abstract

In order to study the application of grouting behind the lining wall in the treatment of leakage of subway tunnel during the operation period, the diffusion effect of grouting behind the wall in dense fill and loose fill was studied by the method of numerical simulation and model test, and the distribution of grouting vein in the process of grouting was analyzed. The results show that the results of numerical simulation and model test are basically the same, mainly as follows: In the dense soil, although the slurry will also expand along the tunnel lining wall, it is mainly jacking in the direction perpendicular to the lining structure, and it is unable to form a large area of enclosed solid behind the lining structure; In the loose soil, with the increase of grouting pressure, the slurry gradually approaches the wall After approaching the wall, it will expand along the wall, and, at the end of grouting, the slurry will be evenly distributed along the back of the tunnel lining structure and form an obvious closed reinforcement. It is concluded that: for the tunnel structure in loose soil, when the measures of grouting behind the wall are adopted to treat the leakage water, the spacing of grouting holes can be appropriately enlarged; for the tunnel in dense soil, the spacing between grouting holes should not be too large. More importantly, the correct grouting scheme design must be considered from the whole reinforced soil, rather than from the effect of a certain point. According to the specific situation and the expansion process of the slurry, the expansion direction of the slurry vein should be considered scientifically, so as to achieve good treatment effect of leakage water.