A method of back grouting for subway tunnel wall

Abstract

The invention relates to a post-grouting method for a subway tunnel wall, which includes a grouting step and a sealing step. The grouting step is specifically: opening a blind hole on a segment, injecting planting glue into the blind hole, inserting a grouting pipe, and grouting The pipe is connected with a ball valve. After the planting glue is solidified, the ball valve is opened. Through the ball valve and the grouting pipe, a through hole is opened at the bottom of the blind hole, and grouting is injected into the ball valve. After the slurry enters the wall of the segment through the through hole; the grouting pipe Including the upper section tube and the lower section tube, the lower section tube, the upper section tube and the ball valve are screwed in sequence, the lower section tube is completely buried in the segment, and the outer wall of the upper section tube is provided with an isolation layer; the sealing step is as follows: the grouting step is completed and the After the set time, separate the upper tube and the isolation layer, take out the upper tube, insert the sealing rod into the through hole to achieve primary sealing; use the bulkhead to seal the lower tube to achieve secondary sealing; use filler to fill the through hole, Three closures are achieved. Compared with the prior art, the present invention has the advantages of simple operation, simple structure and good sealing performance.

Description

technical field [0001] The invention relates to a subway tunnel maintenance technology, in particular to a back grouting method for the subway tunnel wall. Background technique [0002] Subways are becoming more and more popular in various cities. Some cities are located on soft soil foundations. Soft soil foundations are rheologically weak strata with high water content, high void ratio, high sensitivity and low strength. With the increase of subway operation time, Due to the influence of factors such as soil properties of the strata around the tunnel, land subsidence, surrounding construction activities, and vibration loads during train operation, it is easy to cause uneven differential settlement of the overall settlement of the operating tunnel. This kind of uneven settlement is likely to cause water leakage in the longitudinal and circumferential joints of the tunnel segments, and the increase of water leakage diseases intensifies the development of the uneven settlemen...

AI Technical Summary

Problems solved by technology

[0005] After the pre-buried pipe is grouted, it is only closed by the ball valve. After the small pipe is grouted, if the pre-buried grouting pipe is not removed in time, the partially exposed galvanized iron pipe connected to the ball valve will corrode over time due to the humid environment in the tunnel. The gap, the solidified body of polyurethane grout remaining in the pipe shrinks over time, the groundwater or mud outside the tunnel will penetrate into the buried part of the grouting pipe through the gap, and the risk of leakage of the buried pipe is high

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