Numerical Analysis and Vulnerability Assessment of Horizontally Curved Multiframe RC Box-Girder and CFRP Retrofitting of Existing Bridges

Abstract

Given the special geometric features of curved bridges, they show a complex behavior during an earthquake. Considering the fact that bridges have shown vulnerability during past earthquakes, vulnerability evaluation and retrofitting of bridges has become of significant importance. Therefore, this work addressed the impact of different radii of curvature on the probability of seismic damage for curved multiframe concrete box-girder bridges and compared the results with those of straight bridge. The bridge piers were then retrofitted with carbon fiber–reinforced polymer (CFRP). Subsequently, bridge systems were modeled in OpenSEES software subjected to 80 near-fault ground-motion records, considering three components of the earthquake in three dimensions and including all the existent uncertainties. Numerical results indicate that with decreasing bridge radius, the probability of bridge vulnerability substantially increases. Moreover, strengthening bridge piers with CFRP increases median fragility by approximately 32% on average, and thus has a significant impact on reducing the vulnerability of the bridge system.