Reinforcement Technique Research For Urban Concrete Filled Steel-Tubular Arch Bridges

Due to the artistic aesthetics, good structural bearing capacity, higher construction efficiency and lower costs, concrete-filled steel tubular (CFST) arch bridges has been widely used in cities. Since the theories lagging behind the practices, many diseases appeared in many early compelted bridges, reinforcement and maintenance work should be considered. This research is based on the reinforcement design project of the third bridge above Tuojiang River in Luzhou (also named Long-xi Bridge). The key reinforcement technical measures and the new technology of BIM/BrIM were studied for the certain bridge types.Firstly, based on the same type of bridges reinforcement works, five reinforcement design schemes were put forward to deal with the shortage of integrity and dynamic in such bridge. Then, the Midas CIVIL FEM was established in order to acquire the suitable scheme. The adopted bridge deck system transformation scheme was verified. In such scheme, the arch rib concrete stress variation was controled in 1 MPa and the boom vibration appearing in lower moder was effectively restrained. Then the seismic response before and after reinforcement work were compared. The result shows that the changes of inner forces caused by the seismic in the main arch ribs are more than 20%, but the same changes are only 13.54% in load combination. The influence of seismic was limited in such reinforcement scheme.Secondly, to the void question of CFST arch bridge, the ANSYS FEM was established and the influence to the stability and integral rigidity was studied. The different rate of void (0,5%,10%,15%,20%) and different viod type (integral void or partial void) were considered. The influence of void phenomenon was limited on stability, but the influence of integral void was 10% on the integral rigidity. Therefore, necessay measures should be taken to prevent integral void.Thirdly, to the local cracking disease of Long-xi Bridge, the skewback with steel reinforcement and CFRP reinforcement were analyzed to ensure the reinforced results. The analysis shows that both of the 2cm steel plate reinforcement and the double-ply CFRP reinforcement are feasible. Considering the unloaded-load before reinforcement, the most part of the skewback stress varied from -0.26 MPa to 0.7MPa. Considering the 1.3 times live-load after reinforcement, the most part of the skewback stress varied from -5.4 MPa to OMPa.Finally, to the question of the mass and complex O&M informations and the problem of view datas, the Long-xi Bridge BrIM model with O&M informations has been parametrical built by SOLIDWORKS and Revit. By BIM technology, a lot of functions were attained in reinforcement work. Those functions include 3D visualization, checking collision, computing materials consumption, automatic drawing and analyzing the forces. And the technical conditions is given to view and share informations in the following O&M.