Portal temporary plugging structure for shield tunnel and construction method thereof

Abstract

The invention discloses a portal temporary plugging structure for a shield tunnel and a construction method thereof, and belongs to the technical field of tunnel construction. The temporary plugging structure composed of an outer-layer steel ring assembly and an inner-layer steel ring assembly is arranged at a shield tunnel portal, the outer-layer steel ring assembly is fixedly connected to a portal annular beam of a shield end wall, the inner-layer steel ring assembly is correspondingly connected into an outer-layer steel ring through high-strength bolts, and temporary plugging of the shieldtunnel portal is effectively achieved through the inner-layer steel ring assembly which can be quickly dismantled. According to the portal temporary plugging structure, the structure is simple, construction is easy and convenient, temporary plugging of the shield tunnel portal is effectively achieved, the temporary plugging and quick dismantling efficiency is improved, the defect that a large amount of concrete needs to be chiseled away when a traditional temporary plugging structure is dismantled is avoided, the construction amount is decreased, destruction of the chiseling process to a permanent structure is avoided, the tunnel plugging and dismantling construction period is shortened, the construction cost of the tunnel is reduced, and the great application and popularization value is achieved.

Description

technical field [0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a temporary sealing structure for a portal of a shield tunnel and a construction method thereof. Background technique [0002] With the continuous acceleration of the urbanization process in our country, the expansion rate of the city is increasing, and the population of the city is also increasing, followed by various problems that have to be faced in the process of urban development. Among them, the problem of urban transportation has increasingly become the main problem in various problems. In order to meet the travel needs of people in the city, various types of rail transit have been widely used, especially subway rail transit. Occupying ground transportation space, it also has the advantages of large transportation volume, high punctuality, and low transportation costs. Therefore, in the process of urban development, subways often play an extremely i...

AI Technical Summary

Problems solved by technology

[0005] Although the above two methods can realize the temporary sealing of the shield tunnel door to a certain extent, they have some defects and cannot fully meet the high-efficiency and economical construction of the temporary sealing of the shield tunnel door.

Specifically, the first method has the following disadvantages: the permanent structure is easy to be damaged when the portal is chiseled out, the chiseled shape is irregular, and the chiseling workload is large. Welding the shield steel ring, the workload of planting bars is heavy, the construction is cumbersome, the construction efficiency is low, and the construction cost is greatly increased

Although the second method has some progress compared with the first method, because the shield steel ring is pre-buried in advance, the concrete in the area of ​​the portal can be chiseled along the boundary of the steel ring, and only the steel ring needs to be trimmed and polished. It can ensure that the shape of the tunnel door is neat; however, the construction of the second method is relatively cumbersome, the workload of chiseling reinforced concrete is large, and the construction cost is high, which leads to the inability to effectively shorten the construction period of the subway, so there are certain limitations sex

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