Study On Static And Dynamic Performance Of Hybrid Girder Bridge And Steel-concrete Joint Section With Single Box Concrete-multi Box Steel

The hybrid girder bridge with medium span is widely used in the lake area across the plain because of the lower section height of the main girder,and it meets the requirements of the navigation height under the bridge.The whole steel box girder of the traditional hybrid beam usually needs to be welded in the construction site,so the welding work in the box is heavy and the construction progress is slow.For the hybrid girder bridge with medium span in the lake area across plain,the section of steel box girder is generally small and the welding is more difficult,especially the summer temperature is high,the construction condition is bad and the construction quality is difficult to guarantee.Based on this,the single box multi chamber Steel box girder is transformed into single chamber multi box,separated type steel box girder,each steel box is provided with a steel transverse beam and bolted to connect the separate steel box girders into the whole,the whole structure form into the multiple box single chamber steel box girder and single box multi-compartment concrete box girder connection,it greatly reduce the amount of welding in the box,reduce the difficulty of construction and improve the construction efficiency.In this paper,the static and dynamic performance of single box concrete-multi box steel hybrid girder bridge and its joint section is studied with the background of the Huaxi Bridge as follows:Firstly,the Midas Civil is used to establish the whole bridge static model,analyze the displacement and internal force state of each construction stage and the operation stage after the bridge accomplished,and confirm the key construction stage,the most unfavorable load condition and the state of internal forces in the whole model under the most unfavorable load.Secondly,using ABAQUS to establish the local fine model of the steel-concrete joint section,in this paper,the stress characteristics of the steel-concrete section under the key construction stage,the finished stage and the most unfavorable conditions are calculated.the section stresses distribution in the Transition section of the box girder,The transverse and longitudinal stresses in the top and bottom slab of the steel box girder transition section,the stress of the top and bottom plate stiffened rib,the web stress,the stress of solid concrete,the PBL plate and the bearing plate are analyzed.Thirdly,the dynamic response of a mobile vehicle with different speed,different vehicle weight and different driving lanes is calculated by using ABAQUS nonlinear dynamic module.The impact coefficients are calculated by the vertical displacement and longitudinal strain of concrete box girder in the side-span,the steel box in the middle-span and the steel-concrete joint section respectively,and compared with the standard.