Crack Analysis Of Continuous Reinforced Concrete Box Girder Bridge

Continuous Reinforced Concrete Box Girder Bridge has the advantage of flexural stiffness and the torsional stiffness,deck joints less,comfortable journey,and so on. In our country this kind of bridges are in a wide range of applications in recent years. But in the long term found in the use of a considerable number of box girder in the roof, web, backplanes, and other parts of diaphragm has a variety of different types of cracks. The existence of the cracks in the structure has a very adverse impact on durability, safety and the normal use.In fact, if we take the design and construction measure, many cracks can be overcome and control. In order to further enhance the understanding of concrete bridge cracks, in a project to avoid endangering the larger cracks, the paper available in a wide range of related information at home and abroad and more than reinforced concrete box girder crack site investigation on the basis of the closure of a bridge Box Girder study for cracks, the cracks in the concrete bridge type and the reason for the more comprehensive analysis and to facilitate the design, construction identify cracks in the control options to preventive role.In this paper, the content embodied in the following three aspects:1. Summary of the type of bridge cracks and the cause, and closure of a bridge box girder cracks in the background on the bridge project profiles, a more detailed introduction of the Section of the design parameters and the basis for the design of bridge and regulations, using methods and equipment related to the actual situation of cracks in the bridge inspection and statistics. Test results show that structural crack width, length and depth exceed regulatory requirements crack width of the greatest value.2. To a bridge closure of the first box girder bridge accordance with the relevant regulations on the use of Midas software bridge from restrictions stress, deformation under load, the crack width and other aspects of the design verification, and use of large-scale finite element software Ansys on the structure of three-dimensional finite element analysis, analysis of the structural characteristics of the space, a detailed analysis of reinforced concrete box girder webs and the force of the box beam shear lag effect.3. On checking the light of the above diseases and conditions of the bridge, the first statistics of the use of statistics in the current structure of the vehicle load distribution. On consider the current preparation of the lane load. Ansys on the use of three-dimensional structure of the nonlinear finite element analysis, discussion of the structure of the status quo in the cracks under the load causes and the development process for the future structure of the maintenance and reinforcement to provide detailed data. Probably because the high-grade concrete structure of contraction causes cracks have also done a more thorough analysis.The analysis shows that: Overall analysis using planar, Plane inadequate for the analysis of the use of space finite element analysis and correct structural measures, such as the reinforcement and other measures, taking into account that both the general structure of mechanical properties, and take account of the important parts of the complexity of the situation . The results show that this line of thinking does not make the design is too complicated, but also effective solutions for Reinforced Concrete Box Girder Bridge cracking problems.