ABSTRACT
The cables in a cable-stayed bridge are critical components that support long-span girders and ensure their functionality. However, cables are prone to fatigue damage and atmospheric corrosion, which directly affect bridge safety. This study presents a framework for system reliability evaluation of in-service cable-stayed bridges subjected to cable degradation. The effect of cable strength degradation on the system reliability is demonstrated through simulation on the representation of a parallel–series system. Learning machines were utilized to approximate the nonlinear and dynamic response functions of critical components due to cable rupture, and the system reliability finally evaluated from the event tree established by the β-unzipping method. Both short- and long-span cable-stayed bridges were selected as prototypes to investigate the influence of cable degradation on the system’s reliability. On this basis it was revealed that cable degradation can significantly influence the collapse mechanism of a cable-stayed bridge and thereby lead to a significant reduction in system reliability. This phenomenon is associated with cable spacing, where a spare cable system seems more sensitive to cable gradation. The chapter demonstrates that the consideration of cable corrosion and correlation is essential for lifetime safety evaluation of in-service cable-stayed bridges.
