Reaction Response of Horizontally Curved and Skewed Concrete Box-Girder Bridges

Abstract

Concrete box girders are widely used in horizontally curved bridges due to their high torsional rigidity. Certain geographical situation demands skew supports in addition to the curved layout of the bridge and results in complex skew-curve geometry of the deck. The present study focuses on predicting the support reaction response for each unique skew-curve combination of four-cell box-girder bridges via 3D finite element analysis. Central curvature angle for the bridges considered in this paper has been varied from 48° curving left to 48° curving right, at an interval of 12° while the skew angle is swept from 0° to 50° at an interval of 10° to generate feasible combinations possible for skew-curve case. For these unique simply supported multicell concrete box girder bridges, support reactions for dead load as well as for Class-A and Class-70R vehicular live load cases are monitored via large parametric study. Results indicate that uplifting of supports become more prominent in high skew-curve cases at acute corners, while obtuse corner reactions reach as high as 104% of total force transmitting to abutment. Reaction ratio monitored can also be used for deriving skew correction factors for skew-curved bridges.