Study On Construction Control Of Single-Tower Ultra-Wide Hybrid Girder Cable-Stayed Bridge

The hybrid girder cable-stayed bridge combines the mechanical properties of concrete and steel with high efficiency,allowing significant improvements in cross-over capability,mechanical properties,and economy.In recent years,with the continuous emergence of new construction materials,new construction technologies and new construction technologies,the span of bridges has gradually increased,and the width of bridge decks has also been increasing.This undoubtedly brought great difficulties to designers,constructors,and construction control parties.In this paper,the cross-Dongping waterway super large bridge in the trial section of the new public transportation system in Nanhai District of Foshan City is studied.The core technology of construction control for cable-stayed bridges with single-tower ultra-wide hybrid beams is studied in depth.The main research contents and conclusions are as follows:(1)By using the finite element software BDCMS,the static analysis of Jiayu Bridge is carried out to get the force and displacement of the whole structure.Considering the geometric nonlinearity and shrinkage and creep effect of long-span cable-stayed bridge,Force,as well as the tower parameters into the state of the bridge(lower crossbeam support force and the pylon internal forces,stress,displacement).(2)Analyze the influence of the most common types of errors in the construction control on the main beam alignment,which is generally the weld shrinkage,temperature,local deformation of the bridge deck and lateral deformation of the steel box girder during lifting.For these errors,the formula for calculating the correction error is given.Based on the actual situation in the field,the specific method for reducing or avoiding the error is given.(3)Introduce the lateral force and deformation of the box girder during the bridge construction phase and the completion phase of the bridge.The lateral spatial effect of the box girder is significant.During the construction phase,some steel plate dents appear at the front fulcrum of the deck crane,leading to the phenomenon of The stress of bridge decks has abruptly changed.In general,the stress of steel box girders of cable-stayed bridges during the construction phase is small.The lateral displacement of the steel box girder during the construction phase is relatively large,and the code board can be used to eliminate the wrong station.However,during the construction,attention should be paid to eliminating the local stress.During the entire steel box girder construction and bridge formation stage,the maximum stress of the box girder is at the lower edge of the box girder diaphragm.During design,the steel plate can be reinforced.(4)Introduce and analyze the core technologies of the construction control of the cable-stayed bridge of the cable-stayed bridge with ultra-wide hybrid tower,including temperature influence and linear control.Combined with the situation of the construction site across the super bridge of the Dongping Waterway,the process of the precise closure of the Helong section was introduced in detail,and the stress and line shape of the Helong rear bridge were analyzed.