Study On The Structure Optimization Of Steel-Concrete Composite Arch Bridges Erected By Rotating Down Vertically

In this paper, on the basis of having summarized the structure system of prestressed concrete rigid frame arch bridges erected by rotating columns down vertically, it is the structure system of steel-concrete composit arch bridges erected by rotating down vertically that was discussed; Structure optimization theories were applied to develop the optimum rib section design program and the optimum axis program; Two programs were used to optimize the structure of a pilot project such as Wangsheng Zaodu Bridge; It is the statics performance of the income structure of optimum design that was verified finally. The main content is as follows:1. In terms of conceptual design of the structure, it is the origin and idea of prestressed concrete rigid frame arch bridges erected by rotating columns down vertically and steel-concrete composite arch bridges erected by rotating down vertically that was explained separately. The conceptual design of each pilot project was introduced, and the both two were compared with general arch bridges to analyse their pluses and minuses and scope of application.2. On the basis of having discussed the design variable of the rib section optimization of steel-concrete composite arch bridges erected by rotating down vertically, the optimization mathematics model was set up. The genetic algorithm was applied to the section optimization of steel-concrete composite arch bridges firstly. Visual C++6.0 was used to develop the optimum section design program which included the structure analysis module.3. The concept of rational axis was discussed. In the view of the characterristic of line shape of steel-concrete composite arch bridges erected by rotating down vertically, the design variables of the axis optimization were confirmed, and the optimization mathematics model was set up. The linear programming theory was applied to the axis optimization. Visual C++6.0 was used to develop the optimum axis design program which included the structure analysis module.4. Two optimum design programs that author develop were used to optimize the rib section and the axis of the pilot project, and the optimum structure was drawed; MIDAS/Civil6.7.1 was used to carry on statics analysis to the income structure of optimum design in order to prove whether the structure design meets the request of standard.