STUDY OF THE TENSION WITH CONTROL OF TENDONS IN CURVED PRESTRESSED LONG SPAN CONCRETE BRIDGE GIRDERS

The use of prestressing in curved large span bridges results in new problems to analysis and construction. Especially, some problems in construction have to be solved, for example, friction coefficients and curvature change, which would affect significantly the distributing of prestressing in tendons. The available mechanics models are helpless to solve these problems. It is necessary to establish a new model that is applicable to the tension of tendons in curved prestressed large span concrete bridge girders. The model of tension under control given in this paper can deal with the above problems, and has been validated in practical engineering. The results are satisfactory. The model can not only solve the problems of friction coefficients and curvature change in practice but also deal with some uncertainties. Constructions with reference to the model have improved the distributing of prestressing in tendons.