Cumulative vulnerability assessment of highway bridges considering corrosion deterioration and repeated earthquake events

Abstract

Civil infrastructure systems when located in high seismic zones may experience multiple earthquake events along their service life. Highway bridges that comprise critical elements of the transportation network are often exposed to harsh environments that exacerbate the structural performance to withstand such repeated shocks. While earthquake occurrences are intermittent in nature, environmental degradation mechanisms such as corrosion deterioration continually weakens the structural capacity. Presently there exists a gap in literature that simultaneously considers such temporally varying multi-hazard threats within a probabilistic framework. This study presents a novel methodology that considers repeated main shock sequences and corrosion deterioration for an index-based estimation of cumulative damage along the service life while considering the associated uncertainties with the earthquake occurrence and the deterioration process. A newly introduced analytical strategy in this study enables the updating of bridge pier section properties reflecting deterioration of an already damaged bridge between subsequent earthquake shock events. The proposed framework is demonstrated on a representative case-study multi-span continuous concrete box-girder bridge in California, United States. The results reveal a significant impact of corrosion deterioration on the seismic damage accumulation under multiple earthquakes and underlines the necessity to incorporate aging effects within bridge asset management in high seismic zones.