Evaluation of Pylon Shape and Cable Layout Interaction on the Seismic Behavior of Cable-stayed Bridges

Abstract

Nowadays, cable-stayed bridges are among the most widely used bridges. In these bridges, the seismic behavior is critical due to the nonlinear behavior of the cables and the high seismic weight. In recent years, some research has been done on measuring the seismic behavior of cable-stayed bridges. Most of them have evaluated the seismic behavior of the pylon shape or cable layout separately. Nevertheless, it seems very unlikely that these two elements’ reactions do not affect each other. Therefore, this article has tried to consider the mutual effect of these variables in a wide range of span lengths using spectral nonlinear dynamic analysis. On the other hand, the connection angle of the cables to the bridge deck has also been investigated as another variable. The results show that the response of the bridge may change entirely according to the combination of pylon shape and cable layout. For example, in A and diamond-shaped pylons, using a Harp configuration of cables reduces the period of free vibration of the bridge and, as a result, provides the greatest stiffness. On the other hand, the Fan configuration creates more stiffness in the H-shaped and single pylons.