Study Of Long-Span Continuous Rigid Frame Bridge Box Girder Cracks And Its Control Measures

Because of the advantages such as section stress distribution, big tensional stiffness, less bridge expansion joints, and comfortable driving, long-span prestressed concrete continuous box Girder Bridge is widely used in bridge engineering of our country. However, along with a great quantity of construction, its weak links constantly exposed out, a common example, web cracks during the construction process. So aiming at this problem, I made research from the following aspects:1. Combining with practical engineering examples, finite element simulation of the bridge using Midas was made in this paper, and bearing capacity and stress of box girder web plate before and after it cracks was analyzed. It turned out that, box girder cracking result in structural carrying capacity decreased, making the deformation bigger and tensile stress increased obviously.2. Finite Element Analysis indicated that the reason why web crack: concrete strength is insufficient when longitudinal prestressed reinforcement was tensioned; the vertical prestressed reinforcement did not meet the design requirements.3. Researched control measures for long-span prestressed concrete continuous rigid-frame box girder construction cracks, and interpreted that from design, construction, repairing and strengthening. Also, Through the finite element analysis, the effect of paste the reinforcement method is verified.The results of research in this article have certain reference value in design, construction, repairing and strengthening for this kind of bridge.