Damage accumulation In aging highway bridges considering multiple earthquake events

Aging highway bridges exposed to harsh environmental conditions and located in active seismic regions may reveal a cumulative increase in earthquake-induced damage along their service lives when compared to pristine structures. While environmental degradation mechanisms are typically continuous throughout the lifetime, earthquake shocks are intermittent that depend on the seismicity of the region. Among different aging mechanisms commonly observed in bridges, this study focuses on corrosion deterioration of critical bridge components such as bridge piers. A framework is proposed that simultaneously considers multiple earthquake occurrences and corrosion deterioration of bridge components in determining the damage accumulation. Along with the statistical uncertainty associated with corrosion deterioration and occasional main-shock occurrence, uncertainties stemming from material properties is also considered in this study. For a representative case-study bridge in California, an appreciable increase is observed in the cumulative damage index while considering the effects of corrosion deterioration as compared to pristine bridge structures.