The Concrete Shrinkage And Creep Effects Analysis Of Rigid Frame-Continuous Girder Bridges

With the rapid development of highway construction, long-span prestressed rigid frame-continuous composite girder bridge which have the T-rigid frame bridges and prestressed concrete continuous beam bridge advantages has been widely used in recent years. However, during the construction process of rigid frame-continuous composite girder bridge, will be subjected to a number of factors. Shrinkage and creep as the inherent property of concrete have prodigious effect on bridge alignment and stress during the construction and operational course of bridge. During the design and construction of rigid frame-continuous composite girder bridge, The concrete shrinkage and creep are important problem that can not be avoided.This paper detailed explains the concrete shrinkage and creep mechanism, effective factors, and calculative theory and method. Based on Kuyehe bridge as engineering background, Applying the soft of Midas/Civil in the bridge to imitate and finite element analysis. Through the parameter sensitivity analysis of the shrinkage and creep coefficient in our country current norm-JTG D62-2004"Code for design of reinforced concrete and pre-stressed concrete highway bridges and culverts" and drew a conclusion that the influences of the average relative humidity and the strength of concrete for the shrinkage and creep were much more significant than the relative thickness and concrete age of loading. This can provide some references for improve the calculation accuracy of shrinkage and creep.Discusses the influence rules of shrinkage and creep impact on rigid frame-continuous girder bridge’s beam linear, internal forces and pre-stress loss. Known that have significantly affect on rigid frame-continuous girder bridge’s beam linear and internal forces. As the construction progresses, cantilever deflection gradual increase caused by concrete shrinkage and creep; The influence of stress on mid-span is two times than the stress influence on the side spans; Pre-stress loss is distinct at different beam segment locations, with the increase of the distance from the bridge pier pre-stress loss much more, at bridge pier is least.Sensitivity analysis results of major controllable factors about shrinkage and creep showed that with the curing humidity and curing temperature increasing the concrete shrinkage and creep decreasing, but with load ranked and pre-stress loss increasing the concrete shrinkage and creep also increasing. We can take effective measures to minimize concrete shrinkage and creep during the construction process according to the analysis...