Seismic Response of Curved Steel Box Girder Bridges

The results of a comprehensive study of the seismic response of curved steel box girder bridges are presented. Multiple‐span bridges with up to five spans are analyzed. The bridge is modeled using 3‐D space frame elements and El Centro earthquake accelerogram is used as a dynamic input to calculate the maximum responses at the bridge deck and columns. Different elements of the bridge model and the seismic loading are examined, and a comparison between the response history and the response spectrum methods for analyzing curved bridges, using El Centro earthquake accelerogram, shows that the latter technique fails when vibration modes with relatively high frequencies are considered. The simultaneous application of the earthquake loadings in the three global directions is also discussed. Parametric studies are performed and the effect of the span length, radius of curvature, bridge weight, and column geometry are presented.