Research On Stability And Ultimate Bearing Capacity Of Concrete-Filled Steel-Tube Arch Bridge

Because of its unique merit, concrete filled steel tube (CFST) arch bridge is widely used. Along with span increasing and the load of the arch rib increasing, the kind of bridge appears the outstanding problem of its stability and supporting capacity during the construction stage and operation stage. So the research of the stability and supporting capacity of Concrete-Filled Steel-Tube Arch Bridge have great engineering value and theory significance.In this paper, the research results of domestic and overseas scholars on stability and supporting capacity of Concrete-Filled Steel-Tube Arch Bridge are roundly summarized and the theory of FEM(finite element method) to analyze the stability and supporting capacity of Concrete-Filled Steel-Tube Arch Bridge are introduced in detail. This article takes the Hanzhong city Hanjiang River city CFST arch bridge as the project background, uses ANSYS as the tool, analyzes stability and supporting capacity during the construction of the steel tube-confined concrete and five kinds of the operation stage in three ways which are linear elastic stability analysis, geometrical nonlinear stability analysis and double nonlinear stability analysis. This paper also analyzes the influence to the stability and supporting capacity of Concrete-Filled Steel-Tube Arch Bridge by some parameters such as: the ratio of the arch height and span, the link of the arch rib and the excursion of the arch axes. Find out the stability and supporting capacity change rule by this physics and geometry characteristic target. Provide significative reference to help design and build this kind of bridge. But the objection that ANSYS can't consider crack of the concrete in the steel tube by its beam element is found.In allusion to the scarcity of ANSYS, this paper devises a program, which chooses the stress-strain curve which can consider crack of the concrete, uses the theory of spacial FEM, the research fruits of Concrete-Filled Steel-Tube, improves special Cranston method is exploited and validated in this paper. It can process double nonlinear stability analysis of Concrete-Filled Steel-Tube Arch Bridge and consider crack of the concrete. By using the program, a parallel analysis with ANSYS on a single concrete-filled steel tube arch rib. The result shows that the program is fairly accurate and the crack of the concrete in the steel tube lowers the stability and supporting capacity of Concrete-Filled Steel-Tube Arch Bridge rather rapidly.