Shield portal expanding transformation construction method

Abstract

The invention relates to a shield portal expanding transformation construction method. The method is used for construction that the diameter of an original portal ring is 6700 mm and the portal ring diameter reaches 7100 mm after expanding. The method comprises the following steps that (1) setting out is carried out on the center of a designed portal; (2) after positioning and setting out are completed, an original portal ring steel plate and a lining are chiseled off according to a chiseling-off line; (3) after the portal ring steel plate and a lining wall are chiseled off and finished, steelbar planting and drilling are carried out in the long side direction and the short side direction of the portal ring L-shaped steel plate; and (4) the portal ring steel plate is divided into six equal parts, the six equal parts are primarily fixed on a wall, firstly, the two ends of each steel plate are primarily fixed, the roundness and the inner diameter of the portal ring are checked and rechecked after all the steel plates are primarily fixed on the wall, and adjusting is carried out according to the rechecking result. According to the construction method, the defects and risks of a previous construction method are avoided, the workload is reduced, the construction risk is small, the strength, rigidity and waterproofness of the newly-manufactured portal ring meet the design requirements, meanwhile, the structural boundary of a station is not affected, and the construction method can be suitable for all working conditions of similar projects.

Description

technical field [0001] The invention relates to a construction method for opening a diameter-enlarging reconstruction at the connection position of a new section and an old section of a rail transit line. Background technique [0002] In rail transit engineering, due to the adjustment of the design and planning scheme of the new and old sections of the same line, the diameter of the tunnel in the newly designed section is larger than that of the constructed section, so the section project connecting the new and old tunnels needs to adopt a matching large diameter The shield machine of the tunnel is under construction, that is to say, the diameter of the original station portal cannot meet the construction requirements of large-diameter shield tunnels, and diameter expansion reconstruction is required. In the past, similar constructions generally adopted two schemes: [0003] Option One: [0004] Such as figure 2 , as shown in 3, after the entire lining wall 3 and the hole...

AI Technical Summary

Problems solved by technology

[0008] 3. The construction process is complicated and the operation time is long;

[0009] 4. Since the construction needs to chisel out the entire lining wall to the ground wall, construction risks such as ground wall leakage and structural deformation may occur

[0013] 1. Although the construction process has reduced the chisel removal process compared with plan 1, there are still subsequent processes such as planting bars and steel bar binding, which still require a long construction period;

[0014] 2. After the operation of "pasting cakes", there is an impact on the boundary size of the station, and the applicability is not strong

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