A delayed grouting method for single shield tbm wall

Abstract

A wall back delay grouting method for a single shield TBM is characterized by comprising the following steps that before grouting, whether grouting equipment operates normally is checked, whether a grouting pipe is smooth and whether a hole cover of a lifting hole is screwed or tightened are checked, and cement paste is prevented from flowing out of the lifting hole during grouting; the grouting point is selected in the position which is at the distance of 90 m from a tunnel face; grouting adopts a left and right alternation and mutual supplement method, and the grouting pressure is controlled to be 0.2-0.3 MPa; grouting quality is checked and the equipment pipeline is cleaned timely after grouting. According to the wall back delay grouting method for the single shield TBM, the characteristic that the slurry setting time is short is used, group grouting is performed, wall back grouting triangular drainage basins are mutually overlaid, the tight effect of wall back grouting is realized, finally pea gravel, the slurry and the pipe sections are formed into a whole part, forming pipe section staggering is reduced, and the tunnel water permeability is reduced.

Description

technical field [0001] With the improvement of tunneling speed and segment lining efficiency of full-face tunnel boring machine (TBM), it is widely used in tunnel construction. Excavation, prefabricated segment lining, and post-grouting of segment wall are the main control links in construction. Prefabricated The structural size of the segment, the concrete strength of the prefabricated segment, and the quality of post-grouting of the segment wall are fundamental to ensure the quality of the lining. Background technique [0002] With the continuous innovation of single-shield TBM technology, single-shield TBM is more and more widely used in the domestic subway field. Bean gravel dredging and grouting technology plays an important role as an important process of single-shield TBM construction in rocky substratum. However, since the single-shield TBM did not keep the pressure during the excavation process, synchronous grouting was performed in time after the previous dredging...

AI Technical Summary

Problems solved by technology

However, many problems exist in the synchronous grouting. Since the synchronous grouting position is located outside the shield tail, it often causes the shield tail to leak and the slurry to flow into the cutter head, which pollutes the equipment, is difficult to clean, and wastes the grout, resulting in uneven grouting behind the wall. , the cavity behind the wall is formed to cause water leakage in the tunnel; in addition, the slurry flows into the cutter head and the cutter head is sealed, which seriously affects the operation of the equipment

At the same time, the slurry will flow into the gap between the shield body and the rock formation through the gaps in the surrounding rocks, eventually causing the shield to jam and the construction cannot continue

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