Determination of reasonable construction tension of concrete inclined pylon cable-stayed bridge with backstays

A new type of bridge is the concrete inclined pylon cable-stayed bridge with backstays, which is different from the conventional cable-stayed bridge in structure and mechanical behavior. In order to ensure construction quality and safety, it is necessary to determinate reasonable construction tension. First, the reasonable finished state is determined through minimum bending energy and influence matrix method; then, the backward analysis is carried on. During backward analysis, it is necessary to consider the influence of geometric nonlinearity, shrinkage and creep, and the influence of both shrinkage and creep can be dealt with through equivalent nodal force. The whole process can be performed by means of FEM program ANSYS and its secondary development. This method is applied to Banfu no.2 bridge, which is under construction. The analysis results show the cable tension is close to design value, and it is applied to construction computation. The stress state of both girder and pylon can satisfy the Design Code. Hence, it shows this method is simple and effective.