Seismic performance degradation of reinforced concrete bridges under climate change

Abstract

Under climate change and long-term service conditions, durability problems caused by steel corrosion and concrete deterioration severely weaken the seismic capacity of bridges. In response to the limited existing studies concerning the variation in bridge displacement response due to corrosion deterioration, this study utilizes a four-span continuous beam bridge as its engineering background. It investigates the effects of material performance degradation on structural seismic performance. By introducing reduction models for the mechanical properties of steel and concrete, the bridge was simulated using a finite element model in which corrosion damage was explicitly considered. The dynamic behavior of the bridge was evaluated through nonlinear time-history analysis, with emphasis on the coupled influence of corrosion severity and earthquake intensity. Structural response patterns were found to be strongly affected by the characteristics of the selected ground motions. The maximum displacement under near-field pulse earthquakes does not increase with the severity of corrosion, whereas pier-top displacement under far-field non-pulse earthquakes is linearly correlated with the corrosion level. The amplitude of peak displacement is mainly governed by Peak ground acceleration (PGA), and an increase in PGA results in a significant amplification of the bridge displacement response.. In addition, under far-field earthquakes, climate change and service life exert a more noticeable impact on the response, while their effects are overshadowed by pulse characteristics in near-field pulse events. Overall, near-field asymmetric pulse earthquakes produce the largest peak displacements, while far-field non-pulse earthquakes produce the smallest. This study offers valuable insights for the seismic evaluation of bridges affected by corrosion-induced deterioration.