Research On Railway Long-Span Cfst Arch Bridge Construction Control And Stability Durding Construction Stage

Modern long-span concrete filled steel tubular (CFST) arch bridges usually adopt cable stayed cantilever erection and supporting method to build. The displacement and internal force during construction stage vary with the process of construction, and differ from the completed bridge state. In order to guarantee constructive safety and quality of line form and internal force of the bridge, it is necessary to make research on construction control and stability during construction of CFST arch bridge.This thesis introduces the organization system and technology system of construction control of CFST arch bridge, and points out that reasonable construction control is a key factor to ensure successful closure of arch ring. Some research on key technology of construction control is also made.Forces in cable stays are one of the key parameters in the application of cable stayed cantilever erection method. This thesis uses optimization module of finite element analysis (FEA) software ANSYS to calculate one set of cable forces. This set of cable forces are well distributed, and meet the construction safety requirement. It also results a small prearranged height during construction stage.The stability of CFST arch bridge during construction is prominent. This thesis uses FEA software MIDAS/Civil to analyse stability of every construction step, and make some research on parameters influencing stability of the structure. The construction quality of concrete inside steel tubes has direct influence on safety of completed bridge, so this thesis analyzes and compares different sequence plan of pouring concrete, and proposed the reasonable sequence plan.