Method for improving cracking resistance of hogging moment area of steel-concrete composite beam bridge

Abstract

The invention relates to a method for improving the crack resistance of the hogging moment area of a steel-concrete composite beam bridge. When the steel beam is manufactured, fulcrum settlement pre-lifting is considered, after the concrete bridge deck slab is combined with the steel beam, multi-fulcrum cooperative precise settlement is achieved through a PLC system, and pre-pressure is applied tothe bridge deck slab; and settlement pre-elevation of each supporting point is determined according to the anti-cracking requirement of the bridge deck, and the conventional pre-camber is superposedto serve as the designed pre-camber of the steel beam. After the concrete bridge deck slab is combined with the steel beam, the PLC multi-point hydraulic control system is used for controlling the jacks at all pier positions, multi-support cooperative beam falling is achieved, and it is guaranteed that the bridge deck slab is in a pressed state all the time in the beam falling process. Compared with a conventional fulcrum settlement method for applying bridge deck slab prestress, pier-by-pier jacking, concrete pouring, settlement and other operations are not needed, synchronous concrete pouring at multiple fulcrums can be achieved, accurate and cooperative beam falling of the multiple supports at all the fulcrums can be achieved, the work efficiency can be improved, and the construction period can be shortened.

Description

technical field [0001] The invention relates to the technical field of bridge engineering, in particular to a method for improving the anti-crack performance of a steel-concrete composite girder bridge in a negative moment zone. Background technique [0002] Steel-concrete composite beams have the advantages of high bearing capacity, good ductility, and high rigidity, and have been widely used in highways, railways, and urban overpasses. However, for ordinary continuous composite girder bridges, the concrete bridge deck in the negative bending moment area of ​​the intermediate support will withdraw from work after being pulled and cracked, resulting in a decrease in section stiffness and bearing capacity. In addition, cracked bridge decks are likely to cause corrosion of steel bars in the concrete and affect the structure. This shortcoming limits the application of steel-concrete composite beams to some extent. In order to delay or restrain the cracking of the concrete slab...

AI Technical Summary

Problems solved by technology

For multi-span bridges, it is necessary to carry out processes such as jacking, pouring concrete, curing, and dropping beams one by one. The construction efficiency is low and the construction period is long, which limits the application of this method.

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