The Study Of Urban Viaduct Heterotypic Curved Steel Box Girder Spatial Mechanical Behavior

Because of its light weight, large capacity of spanning in both longitudinal and transverse directions, short fabrication and installation period and so on, steel box girder is widely applied to irregular bridge structures. This paper used the finite element method to study spatial mechanical behavior of heterotypic curved steel box girder bridge at western bus station in Changsha and the following work was completed:1. Finite element models of this bridge was established by MIDAS. Then the stiffness and strength of the bridge were analyzed. Under operation of live loads the displacement of the main span is52mm; Under action of the load combination I, the maximum principal stress is140MPa, the maximum shear stress is66MPa; Under action of the load combination II, the maximum principal stress is150MPa, the maximum shear stress is95MPa; elastic buckling eigenvalue of the bridge is5. The results show that:the bridge is in reasonable condition, and the stiffness and strength meet design requirements.2. Formula for elastic buckling critical load of singly symmetric web-tapered steel cantilever beam with a concentrated load at the free end was derived based on the total potential energy of the stability theory in this paper.3. The effects of reinforced concrete plate thickness on elastic buckling load of web-tapered steel cantilever beam was studied by ANSYS. And the results show that:Considering both force performance and material saving, when the thickness of reinforced concrete plate is designed at6cm or8cm, the structure is most economical and reasonable.4. The effects of reinforced concrete plate on composite slab mechanical performance were studied, the greater the stiffness of reinforced concrete plate is, the more even the forces on the composite bridge deck are. Both thickness and concrete elastic modulus are main influencing factors for the stiffness of Reinforced concrete plate, a comparative analysis of the effects of the two factors on composite deck mechanical behavior was made in this paper.5. Both U rib thickness and height are affecting factors of bridge deck stiffness, in this paper, the effects of U rib thickness and height on steel bridge deck and composite deck were analyzed and compared with each other.The research in this paper can provide reference for the design of the same type bridge.