Construction method of urban tunnel branching port with box type top plate structure

Abstract

The invention discloses a construction method of an urban tunnel branching port with a box type top plate structure. A box type top plate comprises upper plates and lower plates which are arranged between the side walls of a tunnel at intervals, wherein main port end plates are arranged at one ends of cavities enclosed by the upper plates, lower plates and the side walls of the tunnel, and branching port structures are formed by the other ends of the cavities through side beams and outer branching port end plates. The interiors of the cavities are divided by webs into a plurality of boxes arranged in the longitudinal direction, mould removing holes are formed in the upper plates of the boxes, and ventilation drainage holes are formed in the lower plates of the boxes by using waterproof mortar to find the slope. The construction method mainly comprises the steps that foundation pits are excavated; concrete is poured on tunnel bottom plates, side walls and embedded columns of branching ports; concrete is poured on the lower plates, the webs, the side beams, the main port end plates, the branching port end plates and the upper plates; and finally a waterproof layer is arranged, and the backfilling of covering soil is carried out. According to the construction method, the self-weight of the structural top plates can be reduced, the thickness of the covering soil of the structural top plates is reduced, loads on the structure are reduced, and the span of an urban tunnel section is increased.

Description

technical field [0001] The invention relates to the technical field of municipal engineering urban tunnel structure design and construction, in particular to a construction method for an urban tunnel bifurcation with a box-shaped roof structure. Background technique [0002] With the development of urban tunnel construction, its functional requirements are getting higher and higher. In most cases, urban tunnels only need to meet the traffic demand in one direction, but sometimes it is necessary to consider the diversion and connection of traffic in multiple directions. Under normal circumstances, the cross-sectional span of the urban tunnel structure at the bifurcation will gradually increase, the plane shape is complex and irregular, and the design and construction are very cumbersome. At present, the roof of urban tunnel bifurcation is mostly in the form of flat plate structure, and its structural design is controlled by crack resistance design. The thickness of the roof ...

AI Technical Summary

Problems solved by technology

Under normal circumstances, the cross-sectional span of the urban tunnel structure at the bifurcation will gradually increase, the plane shape is complex and irregular, and the design and construction are very cumbersome

At present, the roof of urban tunnel bifurcation is mostly in the form of flat plate structure, and its structural design is controlled by crack resistance design. The thickness of the roof is generally large and the amount of reinforcement is also large, so the economy is poor; further, when the buried depth of the tunnel structure roof When it is larger, it cannot effectively reduce the covering soil thickness

If it is designed as an arched roof structure or a folded roof structure, the shape of the roof is neither symmetrical nor regular, the structural form is not reasonable, and the construction is even more inconvenient

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