Paper Title: Seismic fragility of highway bridges considering improved bearing deterioration modeling

Shivang Shekhar, & Jayadipta Ghosh

2018-04-01

Past literature on seismic fragility assessment of aging highway bridges primarily focus on corrosion of bridge columns, with little attention to deterioration of bridge bearings. Corrosion of bearing assemblies can lead to unexpected behavior under seismic loads. For instance, while corrosion of anchor bolts and keeper plates may lead to reduced bearing lateral strength, accumulation of corrosion byproducts lead to “frozen” or “locked” bearings restraining free movement during earthquake events. Limited studies on the analytical modeling of bearing deterioration often adopt simple and potentially unrealistic assumptions on the degradation mechanism. Addressing these gaps, this study develops improved bearing deterioration models based on available field investigation and experimental data. These models are utilized to study the impact of corroded steel bearings on the component level seismic fragilities of a case-study bridge. Results reveal the criti-cality of considering realistic bearing degradation models for bridges located in seismic regions and undergoing corrosion deterioration.