Space Analysis And Simulation Of The Disease Of Prestressed Concrete Box-girder

As the closed box section has a good overall, large torsion stiffness and can provide concrete roof and floor of the pressure area, it is widely used in large-span bridge structure. With the large number of concrete box-girder bridges have been built, the disease of them become very serious, especially inclined web cracks has almost become a common problem, analysis for the box-girder bridge's disease becomes very necessary, and this is the urgent need of the box-girder bridge strengthening.This paper describes in detail the mechanical characteristics of box girder bridge and the major research methods, in this basis, use the ANSYS to establish an improved space model to analyze the box girder bridge as a whole. In the analysis process, first studied the spatial effects of the box-girder bridge, found that the current shear stress amplification factor to consider too small, the calculation of the shear lag effect is also partial in insecurity, which appeared for the box girder section to create the conditions for disease, then based on the various space effects have been considered, the principal stress on the box-girder bridge is analyzed, obtained the principal tensile stress is too large to a box-girder bridge, this is the key reason for the cracks in beams, then this paper analyze the consequences of the disease, found that the bottom slab cracks can cause other various diseases, after that , this paper analyze the effect of radial force on the prestressed box-girder bridge. Finally, this paper use ANSYS to establish a spatial model to analyze temperature effect of the box-girder bridge, full analyze of a variety of different factors on the impact of concrete box girder disease.