The Study On Load-carrying Influence For The Arch Deformation Of CFST Arch Bridge With Long-span

After years of development of concrete filled steel tubular structure,its ultimate load-carrying calculation has formed four basic theory system. Abroad, concrete filled steel tube design procedures are not the same. Although each rule and calculation method is not the same, each study is based on the basic performance concrete filled steel tube, so the results obtained the same. As concrete filled steel tubular structure has the good three direction compression characteristics respectively, the rules give detailed algorithm to the strength and stability calculation of single round steel tube of axial compression and eccentric loading. Because of the complexity of the spatial structure of steel and self state constitutive relationship of concrete materials of CFST arch bridge, its limit bearing capacity calculation theory is complex, so far it has not fully formed unified theory. However, nowadays it mainly divided into arch in-plane and arch surface. The stability analysis of concrete filled steel tube arch bridge is usually divided into elastic buckling analysis and nonlinear buckling analysis. The former based on elastic buckling theory, and its computation is simple; The latter need to perform analysis by finite element theory.It is more complex.but it improves the ultimate bearing capacity calculation concrete-filled steel tube arch bridge and produce the precision of great practical significance. This article analysis the local component through the someone bridge construction appeared in the process of deformation of the steel tube arches.it mainly includes the following several aspects:①It detailedly described and compared the research and discussion on the stress characteristics of single round steel tube and computing model.②It analysis the CFST arch bridge stability problem related classification and calculation of cylindrical shell,and it analysis and compares he axial symmetric and uniform compression cause asymmetric buckling.③It has the local analysis for the steel pipe deformation to relied engineering.it has elastic buckling analysis by empty steel tube. In the guidance of related theoretical.It deduced the calculation formula of the steel pipe in the ultimate bearing capacity and critical stress after deformation.In the same time,it uses the ANSYS finite element software building the three-dimensional entity model for the steel pipe,and it obtained the corresponding limit bearing capacity and critical stress.by comparing the data calculated by model with the data calculated by the theoretical formula,it decide data validation theory calculation formula of the correctness and feasibility. Finally,it explores the the ultimate bearing capacity of steel pipe deformation reduced degree and the corresponding folding of the ultimate bearing capacity of fold reduction factor. And it reflects the influence for the arch deformation of CFST arch bridge .