Abstract
The number of existing cable-stayed bridge has been steadily increasing within the last decades. The stay cables of these bridges, as the most critical members, are subjected to degradation effects due to fatigue and corrosion, in addition to extreme events, which may cause considerable reduction of the structural performance levels. This paper proposes an approach for assessing the time-variant risk caused by strength degradation of the parallel wire cables of cable-stayed bridges. Additionally, a framework for the risk-based optimum maintenance strategies for stay cables is established. The risk analysis of the structure is conducted using a probabilistic time-variant cable strength degradation model. The optimal cable replacement strategies which yield the minimum cable replacement cost during the service life of the bridge are provided.