Evaluation of Shear Capacity of a Prestressed Concrete Box Girder Bridge unsin Non-Linear FEM

In this paper it is demonstrated how higher load carrying capacity with respect to combined shear and torsion can be determined by non-linear finite element (FE) analyses of bridges. A prestressed concrete box girder bridge, the Kallosund Bridge, was evaluated. The Kallosund Bridge, on the west coast of Sweden, is a 45-year-old, cast in situ concrete bridge with four spans, constructed by the free cantilevering method. The case study presented indicates a substantially higher load carrying capacity than for bridge assessment by conventional design methods. In the non-linear analyses of the Kallosund Bridge, about 40% higher design bogie load than in the initial structural assessment was reached (B = 250 kN), together with the other design loads in the ultimate limit state (ULS), before a shear failure developed for the critical load case studied. By improving the model and with "deformation controlled" loading, an even higher failure load is a likely result.