The Effect Of Local Structure On The Performance Of Curved Steel Box Girder Bridge

In recent years,various kinds of curved grider bridge are used more and more widely in transportation.Because of the existence of curvature causing the complexity of its mechanics characteristic,the thin-walled curved box beam which is a new kind of structure system have the deficiency on overall and accurate analysis to its compliacated structure characteristic at present.Therefore,embarking from the bridge's whole forcing property and considering three-dimensional effect,this paper thoroughly studies the performance of curved steel box girder bridge under uniform-loading; by even better coordinates the relationship between the structure's strength, rigidity and deflection has the extremely important practical significance regarding instructing design work.This paper adopts the individual unit of shell143 and applies material nonlinear and geometry nonlinear FEM Model (finite element method) to exactly simulate and thoroughly analyze the overall behaviors of curved steel box girder bridge under uniform-loading.The load-bearing condition of the curved steel box girder bridge in a variety of situations was really simulated through the calculation and analysis of 20 species of 6 series.The major parameters including the curvature radius,the ratio of height to span,the ratio of height to width,the thickness of web,the stiffener density and the diaphragm density are studied.The main conclusions are:under uniform-loading,to the horizontal box shape steel curved beam,the big development of the plasticity area of end beam reduces the stiffness in torsion, which lead to the instability.In the design of engineering,it should reinforce the support region of beam end by setting up stiffener or extending section of girder to transfer stress and avoid stress concentration;The mainly influeneing factors contains the curvature radius,the ratio of height to span,the ratio of height to width,the stiffener density.Moreover,the effect of the thickness of web and diaphragm density on the load-bearing capacity and deflection of curved steel box girder bridge is comparatively lesser;Settling for strength and stabilization of web,it avoids putting web's carrying capacity down owing to constructing technics by increasing thickness of web and lessening the stiffener;The stiffener density's increase can enhance strength of the curved steel box girder effectively,and stiffener of U can reinforce diaphragm's supporting capacity.In conclusion,the FEM Model can well simulate the behavior of the spacial curved steel box girder bridge under vertical uniform-loading. The effect of various of local structure on the performance of curved steel box girder bridge is analyzed exactly in this paper.The work and the result are very useful for revising design specifications and guiding design of engineering.This paper will play a basic role in the further study on the linear and nonlinear forcing property and stability of the curved steel box girder bridge.