Analysis of the factors contributing to fatigue in the cables of cable-stayed bridges

Abstract

The safety of cable-stayed bridges is mainly relying on the cables and the possible fatigue of these cables has been a concern among designer and researchers for a long time. The main purpose of this paper is to analyse the relative importance of all the factors which may induce fatigue in the cables: static and dynamic effects of live load, pavement roughness, parametric excitation, aerodynamic pressure from traffic, vortex shedding and buffeting. These effects have been evaluated for a wide range of cable-stayed and extradosed bridges which cover most of the present applications of this technology.

This study has shown that the present cable technology and the design rules which are applied nowadays prevent fatigue in the cables. There is room for improvement, thus reducing the cost of the cables but such reduction should consider the conjunction of some of the factors which have been considered in this study, especially the dynamic effects of service loads and vortex shedding.