Mechanical Analyse Of Large Span CFST Arch Bridge Construction Process

In recent years, as a new-type bridge, concrete-filled steel tubular(CFST) arch bridge has been deeply developed in our country's construction, for its own merits and can luckily make agreement with the factual situation of bridge engineering since the Sichuan Wangcang bridge has been built in 1990.In the construction of CFST arc bridge, the tie bars and prestressing cables are stained in different groups and different time. The thrusting force on the arc is borne by tie bars, so the tensile force on tie bar is keeping increasing in construction process. Therefore, the construction process is complex and many factors occur in construction is difficult to estimate. These factors may change the stress and deformation value greatly in some components, so the gap between theoretical value and actual value may be big and cumulative.Taking the example of the first large-span railroad CFST arch bridge (Nilesen bridge), according to the construction process, the static calculations are performed in this thesis with the help of a universal FEM software. Before the construction, the whole process of construction is simulated and in the construction process, the real-time tracking and monitoring are used to cooperate with construction. These methods insure the construction safety and high quality of the bridge and also guide the construction. Based on the technical requirements of design, the stress, strain and deformation in every controlling section and tensile force on every cable is monitored strictly and restricted within allowable ranges.Monitoring in the construction process according to the test results of stress, strain and deformation in every controlling section, each component of the structure can help us find mechanical behaviors of components in every stage of construction. So, the problems can be found and the remedial measure can be taken in time. At last, the construction safety and quality of the bridge can be guaranteed.