Finite Element Analysis on Skew Box-Girder Bridges

Abstract

This study examines the effect of skew angle and span-depth ratio on a reinforced concrete simply supported box-girder bridge. The cross-sectional area of the deck is slightly different for different span-depth ratios. The CSiBridge v.20, finite element method (FEM)-based software, is used to carry out this study. The mesh size is determined by the convergence analysis. Both girders are examined for variations in various responses (bending moment, shear force, torsional moment, and vertical deflection) when subjected to a dead load (DL) and an Indian live load (LL). The bridges are designed as straight if the skewness is up to 20°. The deflection is less in skew bridges, and it increases with span-depth ratio. The lowest value of response is obtained for a span-depth ratio of 10. Skew bridges with a higher span-depth ratio generate less bending moment; thus, the skew bridge is more advantageous than the straight bridge. The equations for the ratios of various responses are derived so that the response of skew box-girder bridges having different span-depth ratio may be calculated simply from the straight one. The findings of this study may be relevant to designers for skew bridge analysis.