Probabilistic Performance Assessment of Retrofitted Horizontally Curved Multi-Frame RC Box-Girder Bridges

Abstract

Bridge horizontal deck curvature and the prevalence of in-span hinges in multi-frame RC box-girder bridges have reinforced this class of bridge to response with unique dynamic behavior during seismic excitations. This paper assesses the impacts of 10 different retrofit strategies on the vulnerability of curved multi-frame RC box-girder bridges with multi-column bents based on nonlinear time history analyses in OpenSEES. Consistent with HAZUS-MH definitions, fragility curves corresponding to four damage states at the component and system levels are developed for various bridge deck radii. The results indicate that combinations of retrofit strategies should be used to enhance the desirable level of bridge performance. Moreover, the most effective retrofit strategy in reducing probable damage for a given intensity is dependent on the bridge deck radius and is a function of the damage state of interest.