Construction method adopting freezing reinforcement to replace shield tail brushes

Abstract

The invention discloses a construction method adopting freezing reinforcement to replace shield tail brushes. The construction method includes the following processes: construction before shield tailbrush replacement and during halt, waterstop ring construction, ground freezing construction, shield tail brush replacement and tunneling restoration. In the process of construction before shield tailbrush replacement and during halt, steel segments with freezing compartments are adopted as two rings of segments which are assembled before tunneling is stopped. In the process of ground freezing construction, heat insulation boards are laid on the inner surfaces of the two rings of steel segments firstly, and then freezing tube banks are laid on the inner surface of each segment of the two rings of steel segments separately; and then, a brine tank in a freezing device is connected with the freezing tube banks to form a freezing liquid circulating pipeline, and brine in the freezing liquid circulating pipeline is actively frozen through the freezing device. By means of the construction method, soil behind a shield tail can rapidly and efficiently form a frozen wall with the average temperature less than or equal to -8 DEG C and the thickness greater than 0.5 m, and it can be effectively avoided that muddy water enters a shield machine when the shield tail brushes are replaced.

Description

technical field [0001] The invention relates to a construction method for freezing, strengthening and replacing shield tail brushes. Background technique [0002] The shield tail brush is located at the tail of the shield main body and is in close contact with the segment. The annular space formed by several rows of shield tail brushes is filled with grease, which mainly serves as a seal to prevent water, mud, etc. from flowing into the shield along the back of the segment. The function is a sealing measure to prevent sand and mud gushing from the tail of the shield. During the construction of shield tunneling, inevitable abrasion occurs between the shield tail brush and the segments. The service life of the shield tail brush is closely related to the grease injection and the posture of the segment. If it is used normally, the service life is generally 2000m. If the shield machine excavates beyond this distance, the tail brush may fail, causing water and slurry leakage at t...

AI Technical Summary

Problems solved by technology

The heat transfer of this freezing and strengthening method is in line contact, and the freezing effect is also poor.

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