Torsional Strength of Horizontally Curved Continuous Reinforced Concrete Box Girder Bridges

The horizontally curved box girder bridges are considered important nowadays because of their low cost compared to the load capacity and torsion moments that they can carry. This study presents a finite element analysis of a continuous box girder bridge using CSI finite element bridge software. Three spans with 40 m length, 12.5 m width, and 2.3 m height are studied. The analysis included different radii of curvature with different loading locations along the transverse direction of a cross-section. Several conclusions were reached, the most important of which is that the torsional moments in the outer face are superior to the inner face, even when loading near the inner face. That is, the torsional moments are affected more by the radius of curvature amount than by the location of the load. In general, the maximum torsional moments increase with the decrease of the curvature radius in the outer face. Nevertheless, the maximum torsional moments decrease with the decrease of the curvature radius in the inner face, except for the case of the curvature radius of 100 m. That can be attributed to the fact that the radius of curvature in this case is considered sharp, resulting in high torsional moments.