A Construction Method for Brace Removal and Secondary Lining in Large-Section Tunnel

Abstract

The invention discloses a large-section tunnel support removing and replacing and secondary lining construction method. The method comprises the steps of cutting off a lower layer middle partition wall, constructing an inverted-arch waterproof structure, constructing a secondary lining inverted arch, cutting off a lateral temporary inverted arch, putting up a full hall scaffold template support system of a secondary lining structure, constructing a lateral wall waterproof structure, constructing a secondary lining lateral wall, cutting off an upper layer middle partition wall, constructing a top arch waterproof structure, constructing a secondary lining top arch, demolishing the full hall scaffold template support system, and cutting off the middle partition walls preserved in the second step and the eighth step. According to the large-section tunnel support removing and replacing and secondary lining construction method, the bearing capacity of the temporary structure itself is innovatively utilized, the temporary structure and the full hall scaffold template support system which is erected during secondary lining construction are combined, a conventional support removing and replacing system is replaced, the bearing capacity of the support removing and replacing system is improved, the primary construction section is stretched to 9 m from 6 m, the construction method of a large-section tunnel is sharply simplified, the content of a construction technology is simplified, the construction efficiency is improved, and the work dangerousness is lowered.

Description

technical field [0001] The invention relates to a construction method of a tunnel, in particular to a construction method for removing and replacing braces and secondary lining of a tunnel with a large excavation area. Background technique [0002] At present, the construction of large-section tunnels usually adopts the excavation method of multiple pilot tunnels, and the common construction methods include the double-side pilot tunnel method and the CRD method. Before the construction of the second lining of large-section tunnels, the temporary structure of the primary lining (middle partition and temporary inverted arch) formed by the primary lining support needs to be removed, so that the secondary lining structure can be closed into a ring. [0003] The demolition of the typical primary lining temporary structure and the construction of the secondary lining structure have the following requirements: [0004] 1. The segmental demolition length of the initial lining tempo...

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Problems solved by technology

[0015] The purpose of the present invention is to provide a construction method for removing and replacing braces and secondary linings for large-section tunnels. To solve the technical problems that the existing construction methods are complicated, the structural stress system needs to be replaced multiple times, which is not conducive to the stability of the structure, and To solve the technical problem that construction in a limited space requires a lot of manpower and material resources, and a large amount of supporting materials are used; it is also necessary to solve the problem that the length of a support removal section is limited, resulting in many construction sections, affecting the construction progress, low construction efficiency, and increasing tunnel construction joints The setting is not conducive to the problem of waterproofing and quality assurance of concrete construction

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