Analysis Of Damage Evolution And Its Influence To The Carrying Capacity About The PC Birdge That Already Haven

In order to adapt to the requirement of rapid economic development， in the pasttwenty years，prestressed concrete bridge has experienced an intensive construction anddevelopment stage in our country. Due to the influence about design, construction,operating environment changes, and other factors, with the service time increasing,many sorts of damage has appeared in the bridge itself, the damage accumulated whenthese bridges continue to serve, So the bearing capacity drops and the normal use of thebridge reduces. In order to ensure the safety of bridges in the process of service, thedamage accumulation effect on the prestressed concrete Bridges’ bearing capacity hasbecome a problem must to be solved.In the prestressed concrete bridges that have been built, prestressed concretecontinuous box girder bridges occupy a high proportion. In order to ensure the researchresult has an extensive applicability, the model of prestressed concrete continuous boxgirder bridge has been choosed to used to study in this article.①This paper analyzed the data of the common steel accelerated corrosionexperiment, obtained the relationship between the corrosion rate of reinforcement andconcrete cover, this relationship applies to prestressed reinforcement.②At the same time, the data on the prestressed steel accelerated corrosionexperiment were analyzed, obtained the formula for the prestressed reinforced sectioncorrosion rates and the stress loss.③In this paper, the prestressed concrete continuous box beam bridge model wasestablished and obtained the relationship between the prestressed reinforced sectioncorrosion rates and the bridge bearing capacity. At this point, deduced the relationshipbetween the bridge bearing capacity and stress loss.④Simulations of extreme weather were carried out by using Midas in this paper,through the analysis of the simulation results can be obtained that the extreme high andlow temperature weather decrease the bridge bearing capacity.⑤Synthetically comparing the factors on the bridge bearing capacity, determined the main factors, combined with the experiment and model data, established therelationship between the flexural capacity of the bridge and time.