Climate Change Considerations for Seismic Vulnerability Assessment of Aging Highway Bridges

Abstract

Aging affected structural components negatively impact the lateral load–resisting capacity and fragility of highway bridges during seismic shaking. Until now, a majority of existing literature on corrosion deterioration of highway bridges assumed a constant or time-varying degradation rate that is independent of initial climate conditions or their variations along service life. Recent research on climate change indicates a time-dependent shift in atmospheric temperature and relative humidity due to global warming. These effects, compounded along the service life with heightened chloride ingress, require careful consideration for bridges located in regions near marine sources and characterized by moderate to high seismicity. The present study proposes a multihazard framework to evaluate seismic fragility of highway bridges considering earthquake hazard, aging effects, and global warming due to climate change. The framework, when demonstrated on case-study multispan continuous steel girder bridges in the central and southeastern United States, reveals that potential climate change effects are likely to further exacerbate the seismic performance of aging bridge structures.