Study On The Simulation Analysis And Control Of Long-span Concrete-filled Steel Tubular Arch Bridge

Based on Yue Hai Bridge (a five-span tied arch bridge with three dumbbell-shaped arch ribs), the three-dimensional space model of the bridge is built by MIDAS finite element software. The simulation analysis of the static,dynamic,stability performance of the bridge in hollow tube stage,pouring concrete into the tube stage,hanging beams stage,the lay channel board stage and the completed bridge stage is carried out. Through contrasting the theory values with the measure ones of lineshape and stress, the consistency of the structure simulation analysis is verified .In the process of building model , the arch rib section is simulated by the MIDAS's combined-section of construction phase. The method of it is conversion of the section.The rib is made up of four parts: dumbbell-shaped steel tube frame, top concrete section, middle concrete section and bottom concrete section.The sections of the concrete are converted into the steel sections. With construction stage going on, the sections are combined one by one. The combination of the sections will be completed untill the steel tube is filled by the concrete actually.In every stages of the construction, the displacement of the middle arch rib on the bridge control section is almost twice of the side ribs's; the stress of the middle ribs on the control section is about 1.5 times of the side ribs's. The lineshape and stress of theoretical results were compared with the measured results and it indicates that the theoretical results and measured are anastomosis.The stability of the buckling through all the bridge construction stages is analyzed. The stability factors are far greater than 4 which indacates that the bridge is very stable in every construction stage. All instability models are in plane of the bridge. It shows that it is very strong in outface. The major control of stability should be in its plane.The sub-space method is used to extract its first 30 vibration models. The response spectrum theory is used to analyze the bridge's reflection in eight degree of the earthquake. The results show that the bridge flexible better. The effects of earthquake in the middle rib and side rib are the same. The results can be used for the bridge's dynamic evaluate.The lineshape and the stress are controlled in an ideal limitation. Construction control is successful.