Influence of Combined Corrosion–Fatigue Deterioration on Life-Cycle Resilience of RC Bridges
Dinesh Kumar Devendiran, Swagata Banerjee
Abstract
Corrosion and traffic-induced fatigue are two major threats to RC bridges in high-traffic and corrosive environments. Coupled interaction of these two mechanisms, referred to as corrosion–fatigue, causes gradual material degradation of bridge girders and leads to an enhanced seismic vulnerability of bridges as deterioration proceeds. In this context, the paper develops a numerical framework to estimate seismic resilience of two RC bridges, having two and three spans, subjected to combined corrosion–fatigue degradation over their lifecycles. Modeling of corrosion–fatigue involves the simulation of fatigue loads on bridge girders using stochastic samples of gross vehicle weights obtained from weigh-in-motion measurements and estimation of fatigue stresses at fatigue-critical locations of bridge girders. Observed time-variant deterioration of bridge girders due to corrosion–fatigue is utilized to develop finite-element models of these bridges, in which piers are also assumed to have corrosion. Analyses result in an estimation of seismic vulnerability and resilience of these bridges in the life-cycle context. Among the two bridges, a three-span bridge is observed to experience higher reduction in resilience with time due to its higher flexibility than does a two-span bridge. Overall, research outcome demonstrated the confronting role of corrosion–fatigue degradation and emphasized its adverse impact on life-cycle seismic resilience of RC bridges.