Simulation Calculation Analysis Of Long-span Composite Steel-box Arch Bridge

As one of the basic style of bridge, the arch bridge, which has a long history, is full of artistic beauty. At present, when China is in the rapid development period of high-speed railway, there have been unique arch bridges. The composite steel-box arch bridge is a new structural system of arch bridge, very few practical engineering applications. It is characterized by the main arch rib, made up of upper and lower arch rib superimposed. It is necessary to research and analyse its structural characteristics and mechanical behavior, etc. The information presented in this paper will provide a reference for the designs and constructions of the similar bridges in the future.In this thesis, by taking the Xinkai River composite steel-box arch bridge as project background, these problems of its spatial static behavior in the finished bridge state, computer simulation for construction process, stability of the state of the whole bridge and characteristics of structure self-vibration are researched and discussed. Main research works of this thesis are included below:(1) The mechanical characteristics the histories of arch bridge are introduced briefly. Make an overview of the development of the long-span steel arch bridges. Briefly describe the structure's characteristics and the main tyepes of tied arch bridge.(2) Briefly discusses the arch deflection theory and derive the geometric equation, the internal force equation and the balance equation. The historical development of finite element theory and its application in bridge structure analysis are described. In additon, the basic process of finite element theory for bridge analysis is briefly introduced.(3) Joining the engineering exam Xinkai River Bridge, the thesis builds up a integrated finite element model. Calculate and analyze the force characteristics of the structure in the finished bridge stage. The influence degree of dead load, live load, temperature load on internal force and deformation of the structure is comparatively analysed. The action of stress and deformation of the structure under the critical load combination is checked, and, the results are met "Railway Code". The influence of different forms of tie beam for static behavior is analyzed.(4) Describe the construction method of arch bridge and the calculation method of the construction process. Construction scheme and construction technological process of Xinkai River Bridge is briefly introduced. By using the flip analysis method, the whole process of the construction of the composite steel box arch bridge is simulated, and, the calculation results of the construction process are discussed and studied.(5) The spatal stability of composite steel box arch bridge in the stage of finished bridge is calculated and analyzed. The conclusion is that the form of the worst instability is out-plane and transverse. The influence of different stiffness of the arch ribs on the stability is analyzed. The viration frequency and forms of the composite steel box arch bridge is researched.