ANALYSIS OF CABLE-STAYED BRIDGES SUPPORTED BY FLEXIBLE TOWERS

An analytical iterative method for the static analysis of continuous cable-stayed bridges is presented. The towers can have any degree of flexibility and the interaction with their supporting media (caissons or piles) is considered. The system is divided into two substructures: the tower and the girder plus the cables. The continuous girder is solved by means of the method of three-moment equations, while the deflections are calculated from Fourier series. It was found that a small number of iteration cycles and Fourier coefficients are sufficient for convergence and a few simultaneous equations are required for solving the entire system. Therefore, large bridge systems with a large number of cables can be analyzed under different loading conditions using the PC computers. A comparison between the numerical results of the present method and those obtained from the nonlinear stiffness method shows the advantages of the present method and also shows that nonlinearity effects are not important for such types of bridges. ©ASCE.