Study On Deformation Control Of Long-span Continuous Rigid Frame Bridge In Construction Stage

The PC continuous rigid frame bridge maintain the advantages of jointless and smooth driving in the continuous beam. And it also maintain the advantages of no bearings and without system transformation in the T-shaped rigid frame. So it has been developing rapidly in modern bridge construction. However, with more and more large span prestressed concrete bridges with continuous rigid frame are built, the girders of this kind of bridge crack during the process, especially the cross-deflection and so on. They affect the normal use of the bridge. Taking the XuShuigou bridge as a subject, this paper studies on deformation problem of large span prestressed concrete bridges in the process.This paper consults a large number of documents, describes the mechanism and influencing factors of concrete shrinkage and creep, summarize calculation method of creep coefficient and shrinkage strain, analyze the impact of concrete shrinkage and creep and prestressing loss on the main beam deformation and stress, generalize the measures of reducing the main girder deflection from the design, construction, management. Based on the results about long-term monitoring for large span continuous rigid frame bridge, we come to the deformation law and stress-strain characteristics of the bridges in operation. Establish a continuous rigid frame bridge model, analyze the impact of concrete shrinkage and creep and prestressing loss on deformation in different specifications, different loading age and different environmental relative humidity.Some research results of this paper were used in the process monitoring of the XuShuigou bridge, and established a solid foundation for scientific management and maintenance of the bridge.