Performance of a Long-Span Suspension Bridge Subjected to Sudden Single Suspender Loss

Suspenders of long-span suspension bridges are thin structural components that are easily accessible to the public and in proximity to fast moving traffic. Their vulnerability and exposure to hazards make them especially prone to the risk of malicious or accidental damage. Albeit, the effect of suspender loss on the behavior and performance of long-span suspension bridges has not yet been thoroughly investigated. In this paper, therefore, using computational simulation, member removal analysis is undertaken to shed light on how a typical long-span suspension bridge responds to sudden loss of a single suspender. Two factors, the location of the lost suspender and live load cases, are addressed in the study. Simulation results show that only structural members in the immediate vicinity of the lost suspender are significantly affected by sudden suspender loss, while the rest of the bridge is hardly affected. The study suggests that single suspender loss scenarios in long-span suspension bridges like the prototype bridge investigated in this work do not trigger appreciable nonlinearity in the system or even cause the main cables to overcome friction at the saddles. As such, single suspender loss scenarios in bridges like the prototype system can generally be assessed using common analysis and design software.