Static And Dynamic Analysis And Stability Research On Concrete Filled Steel Tube Arch Bridge

In China, concrete filled steel tube (CFST) arch bridges have become more and more popular in recent years. It has lots of advantages, such as light deadweight, great strength and strong distortion-resistant capacity. It can preferably satisfy requirements of great need of bearing capacity, simple construction stages and economical materials. It is a kind of more reasonable structure form for long-span arch bridges. Structural characteristics and mechanical properties of concrete filled steel tubular arch bridges need to be researched because of its complex mechanical characteristics.Taken a concrete filled steel tube arch bridge as project background, the finite element models are established based on the bridge structure arrangement, material properties and actual load conditions; static and dynamic characteristics and stability are analyzed and researched according to the concrete filled steel tube structure theory and the finite element theory. The main research contents are as follows:(1) In this paper, structure characteristics and history of arch bridges are introduced. Development status of concrete filled steel tube arch bridge at home and abroad is described. Reasons of the rapid development and the advantages and disadvantages of this kind of bridges are analyzed.(2) Working principle of concrete filled steel tube structure is introduced. And three different theory systems together with relative design codes, which have been wide applied in China at present, are introduced and compared. In addition, the stability theory of arch bridge is described; in-plane buckling and roll stability of arch bridge are derived and calculated.(3) By using finite element software, the mechanical characteristics of the concrete filled steel tube arch bridge are analyzed. The influence of dead load, live load, braking force and temperature load on static response of the structure is comparatively analyzed. The stress and deformation of structure under the key load combinations are checked. The influence of different forms of main beam for static behavior is analyzed.(4) The method of calculating bridge natural vibration characteristics is introduced, and the dynamic natural vibration characteristics of this bridge are calculated and analyzed. Influence of rib stiffness, rib section, lateral brace arrangement and lateral brace stiffness on the natural vibration characteristics is analyzed and compared. (5) Through establishing finite element models, elastic stability of concrete filled steel tube arch bridge is researched. Stability of this bridge under different load combinations is compared; influence of rib section, rib tilt angle, lateral brace arrangement, wide-span ratio on the stability of concrete filled steel tube arch bridge is analyzed and compared.