Detachable U-shaped preliminary bracing method combined with canopy-method construction

Abstract

The invention discloses a detachable U-shaped preliminary bracing method combined with canopy-method construction. According to the method, a method that a U-shaped steel frame and a large-diameter pipe shed are connected is adopted, and the U-shaped steel frame is convenient to mount and can be detached and recycled, so that the construction period and materials are greatly saved; and meanwhile,the carrying capacity of the large-diameter pipe shed is fully exerted, a preliminary bracing is not required to be constructed at the top of a pilot tunnel, a preliminary bracing and a leading pre-bracing (the large-diameter pipe shed) constructed in the preorder form a combined bracing system, and the synergistic effect of a tunnel bracing structure system is fully shown. A new idea is providedfor Collaborative optimized design of the tunnel bracing structure system. The pipe shed and the U-shaped preliminary bracing are sequentially combined from top to bottom as follows: the large-diameter pipe shed, connecting pieces, cushion blocks, adjusting pieces, side wall profile-steel frames (pieces of profiles are connected through bolts), locking foot anchor pipes and bottom grid steel frames (grids are connected through bolts).

Description

technical field [0001] The invention relates to the field of underground cavern construction, in particular to a detachable U-shaped initial support method combined with shed cover method construction. Background technique [0002] With the rapid development of our country's economy, the traffic conditions in the central urban areas of many cities are deteriorating day by day. In order to alleviate the traffic pressure, it is necessary to build urban subways, road tunnels, railway tunnels, and underground crossings under structures such as busy roads, railways, and existing buildings. Passages and other underground projects to ease traffic pressure, disperse passenger flow, facilitate pedestrians to cross the road, and solve the problem of "difficulty crossing the street" for pedestrians. How to ensure that under the premise of safe construction, minimize the disturbance to surrounding buildings (structures) and ensure the normal operation of surface traffic is an urgent pro...

AI Technical Summary

Problems solved by technology

[0004] In the existing technology, most projects adopt the dynamic construction method of small-diameter pipe shed (pipe diameter is only 79-129mm) and grid arch frame with short footage to control the settlement; , due to the complexity of the surrounding environment of the station, small-diameter pipe sheds are no longer suitable for such projects

At the same time, the general tunnel primary support usually adopts a combined structure composed of shotcrete and steel frame or grid steel frame with bolt support, and the combination of large-diameter pipe shed and tunnel detachable U-shaped primary unprecedented

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