Research On Lifting Erection And Control Technology For Long-span CFST Arch Bridge

In our country, concrete-filled steel tubular (CFST) arch bridges have become a new technology of the bridge construction in recent years. It has the merits of light deadweight, great strength and strong distortion-resistant capacity. It can preferably satisfy requirements such as less materials, light erection weight, simple construction, and great bearing capacity. It is a kind of more ideal structure form for long-span arch bridges.The researches and applications about CFST structure have been taken about one hundred years in the world. But in China the researches have been taken since 1950s. Since 1990s, as a new-style combined material with favourable mechanical behaviour fit for arch bridges, CFST has been getting broad application and rapid development. The research in this thesis is concentrated on the design of the cable suspending-fastening system and construction control of fastening-cable forces and arch ring's shape for CFST long-span arch bridges. The main contents are summarized as follow:1. Starting with the introduction of erection methods of arch bridges, different erection methods and their applicability are analyzed briefly. Accordingly, construction issues are pointed out when using CFST for long-span arch bridges. The erection methods of CFST arch bridges are substantially the rigid skeleton method and the self-spanning method. Two main methods of the cable crane-assembly method and the rotation method forming span of steel tube skeleton are emphasized.2. Based on the construction of the Xiaohe Bridge, a deck CFST arch bridge with main span of 338m, the design, calculation and construction method for cable crane system, main pylon system, fasten and hang system are introduced respectively in this thesis.3. On the project background of the Xiaohe Bridge, the optimizing theory and the FEM method are applied to the calculation of the fastening-cable forces in the process of craning construction of the steel-tube arch segment and construction error adjusting. The calculated optimum cable forces with high precision can guarantee the inner forces and the structure deformation in safe state, and ensure the line shape of the arch ring in accordance with design requirements as well.