A Construction Technology of Vertical Prestressed Steel Tube Support for Large-Section Underground Excavation Tunnel

Abstract

The invention discloses a vertical prestress steel pipe supporting structure for a large-section subsurface tunnel and a construction process. Firstly, a lower small guide hole is constructed, and a strip foundation is constructed; then an upper small guide hole is constructed, manual hole digging is conducted on the upper small guide hole so that a vertical channel can be formed, a vertical steel pipe support is installed, a movable end is arranged at the bottom end of the steel pipe support, the support is located on the strip foundation, and a fixing end is arranged at the top end of the steel pipe support and supported by an arch joist steel profile steel longitudinal beam; a free face is formed by the upper small guide hole, the lower small guide hole and the vertical channel, so that the adverse influences of explosion on the steel pipe support are reduced; reliable preliminary linings and the vertical support with high rigidity are quickly formed on an arch, prestress is applied in the digging process according to an information monitoring result, and active control is conducted on deformation of the arch. By the adoption of the technical scheme, the vertical prestress steel pipe supporting structure has the advantages that arch crown settlement can be effectively controlled, the explosion vibration speed is reduced, the temporary support is protected, construction safety is guaranteed, the construction period is shortened, and cost is low.

Description

technical field [0001] The invention relates to the field of tunnel excavation construction, in particular to a vertical prestressed steel pipe support structure and construction technology for large-section underground excavation tunnels. Background technique [0002] At present, most large-section tunnels with weak surrounding rocks are constructed by the double-side-wall pilot pit method, such as figure 1 The construction steps shown: step 1, excavation of the upper left pilot pit ①, initial support; step 2, excavation of the lower left pilot pit ②, initial support; step 3, excavation of the upper right pilot pit ③ , initial support; step 4, excavation of the right lower pilot pit ④, initial support; step 5, excavation of the upper middle pilot pit ⑤, initial support; step 6, excavation of the middle lower pilot pit ⑥, initial support ; Step 7, remove the support, lay the inverted arch waterproof layer, and pour the inverted arch concrete ⑦; Step 8, lay the waterproof la...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a vertical prestressed steel pipe support structure and construction technology for a large-section underground excavation tunnel, which solves the problem of poor safety in the prior art, and achieves the purpose of improving construction safety, speeding up the progress, and shortening the construction period

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