Analysis Of Mechanical Performance Of Continuous Bridge With Plate-Truss Composite Structure During Construction Stage

Continuous steel truss bridge with beautiful shape, strong spanning capacity, span layout flexibility, and the high strength, it is a usual form of long-span bridges.The construction process of long-span bridges will go through a complex process, accompany with the change of construction scheduling, the structural system, load cases and boundary conditions are changing continually, therefore, to ensure the safety of long-span bridge construction, it needs to carry the mechanical properties analysis on the bridge construction process.This article take the second joint of Zhengzhou Yellow River dual purpose bridge as the example, carrying the mechanical analysis on the construction process of the second joint of Zhengzhou Yellow River dual purpose bridge, this artile's main work as follows:1.Using finite element software Midas/civil to establish the space finite element calculating model.In the modeling process, each bar truss is simulated by beam element, portal frame is simulated by truss element, orthotropic steel deck is simulated by orthogonal anisotropic plate.To be directed against the complexities of construction and stress for overall node of steel truss girder, establishing the finite-element computing model of E80 by plate element of Midas/civil, the model includes ribbed stiffener, clapboard and so on.2.According to the plan of construction for the second joint of Zhengzhou Yellow River dual purpose bridge, the steel truss girder is mounted by cantilever erection method, the progress is divided into 9 construction stages, carrying simulation analysis of construction process on deformation of bridge and stress of each bar for each construction stage of construction process, the calculation results show that, when the truss bridge is mounted by cantilever erection method, the deformation of steel truss girder is smaller, the stress value of each bar of steel truss girde is less than the yield strength of steel, the structure is in a safe condition, this plan is feasible.3.Considering the larger force conditions of construction process for the second joint of Zhengzhou Yellow River dual purpose bridge, carrying local stress analysis on the maximal stress node——E80, obtaining the distribution rule of nodal region, the calculation results show that, the global stress level of gusset plate is lower, appearing stress concentration in local region, the stress value is less than the yield strength of steel, the structure is in a safe condition.