Study On Deflection Of Prestressed Concrete Continuous Rigid Frame Bridges

Domestic transport is developing rapidly. Prestressed concrete continuous rigid frame bridge is widely used for the crossing ability and economic factors. But many of these bridges exist the problem of excessive deflection, a serious impact on bridge performance. Therefore, how to control the prestressed concrete continuous rigid frame bridge deflection is necessary.Deflection is mainly affected by prestress loss and shrinkage and creep of concrete.The deflection of prestressed concrete continuous rigid frame bridge is affected by many factors.This thesis mainly studied on the effects the loss of prestressed and the creep and shrinkage of concrete.First of all, the development process of the prestressed concrete continuous rigid frame bridge, this bridge-type advantages and existing diseases, the reasons that affecting the deflection is introduced in this thesis.Second, the mechanism prestress loss is also analyzed. And how the length and arrangement of prestress affect the deflection.Third, shrinkage and creep of concrete is studied. For example, it is analyzed that the factors affecting the shrinkage and creep of concrete and how to calculate it. And the thesis also analysed the factors of affecting the deflection.Fourth, a continuous rigid frame bridge model is studied by Midas/Civil. The impact on the deflection of the prestress and the shrinkage and creep of concrete is studied by the example.Finally, the measures are proposed for decreasing the deflection of the continuous rigid frame bridge. It includes design and construction. At the same time, a "zero moment tensioning cable" arrangement method.