Secondary grouting method for shield tunnel duct piece

Abstract

The invention discloses a secondary grouting method for a shield tunnel duct piece. The secondary grouting method comprises the following steps: A, during synchronous injection of mortar, injecting rapid-hardening mixed liquid into a grouting liquid filling region through a standby grouting pipeline of a shield tunneling machine; and B, during tunneling of the shield tunneling machine or when the tunneling of the shield tunneling machine is stopped, injecting the rapid-hardening mixed liquid to the back of a duct piece lining, which is separated from the shield tail by 4 to 5 rings, through a device temporarily mounted on the duct piece. According to the secondary grouting method for the shield tunnel duct piece, the rapid-hardening mixed liquid and the mortar can be quickly mixed; as the two types of slurry liquid are rapidly hardened, floating up of the duct piece is effectively prevented, and the early stability of the duct piece lining is guaranteed; and in the work of opening a bin to replace a tool in long-distance hard rock construction, the phenomenon that water enters the shield tail and the phenomenon that water enters the shield tail during shield launching and receiving in a water-rich stratum are effectively prevented, and the construction effect is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of shield tunnel construction, in particular to a secondary grouting method for a shield tunnel segment. Background technique [0002] After the shield machine is excavated, there will be a certain gap between the segment and the stratum, and between the segment and the shield tail shell. In order to control the deformation of the stratum, reduce the settlement, and help to improve the impermeability of the tunnel and the lining of the segment In the early stage of stability, it is necessary to fill the grout in the circumferential gap of the wall thickness of the segment by synchronous grouting, which is synchronous grouting. During the grouting process, the slurry is mixed according to the design mix ratio by the mixing station on the ground, and then transported to the slurry truck at the tunnel entrance through the pipeline, and then transported to the supporting slurry storage tank behind the shield mac...

AI Technical Summary

Problems solved by technology

[0004] In addition, in the existing shield construction, the main grouting pipeline is mainly used to inject mortar into the grout filling area synchronously, and the spare grouting pipeline is idle for standby. Such a grouting method is easy to be damaged by the grouting method under conditions such as water-rich strata. The water flow breaks up and reaches the cutter head cabin, and the synchronous grouting effect is poor; if the mortar is mixed with the quick-setting mixture before it is injected into the grout filling area, it may cause frequent blockage of the grouting pipe due to mechanical failure and long-distance transportation road, affecting normal construction

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