Large Span Pc Bridges Shrinkage And Creep Effects Analysis And Research

Shrinkage and creep are time-dependent characteristic of the concrete, for the long-span prestressed concrete bridges, the internal forces and deformations of the structure caused by shrinkage and creep should not be neglected. We must consider the influences during the design and construction.Based on the past research findings, one analytical method for shrinkage and creep effect of concrete was studies mainly in this paper. Age-adjusted effective modulus was used to substitute for concrete elastic modular to consider the shrinkage and creep influences of concrete. Combining age-adjusted effective modulus method with finite-element method, finite-element step-by-step analysis method was studied. Different shrinkage and creep model can be used to simulate the shrinkage and creep developing process of long-span prestressed concrete bridges. The shrinkage and creep model ,that is CEB-FIP1990 model, defined by "Specifications for Design of Reinforced Concrete and Prestressed Concrete Highway Bridges and Culverts"(JTG D62-2004)which is promulgated recently by our country is used in the method.Xintian Yellow River Bridge located in Gansu province was used as project sample in the paper. The shrinkage and creep effects for the internal forces and deformations of the main bridge are analyzed by this method and the computation results were compared with the measured results. From the interpretation of result we can know that the shrinkage and creep effects on the internal forces and deformations of the structure are large, especially on the deformations. The computation results are accordant with the measured results basically. So the method studied in the paper is practical and can be referred.