High temperatures and bridges: Transverse stiffeners in steel girder fire performance

Vehicular accidents involving tanker trucks may initiate devastating fires that can cripple a steel plate girder bridge. An observation of web shear buckling in one case study leads to a discussion on the existing understanding of this phenomenon. A closer look at the contribution of the transverse stiffeners to postbuckling shear capacity focuses on the effects of utilizing diagonal orientations of the stiffeners, as well as providing thermal insulation for the stiffeners alone. It was found that the diagonal stiffener models do not offer much improvement to the postbuckling shear strength compared to the use of the traditional vertical intermediate stiffener. Given the complexity of attaching a diagonal stiffener, it appears that the vertical stiffener is the better option. Further, providing fire resistance solely for the stiffeners was found to offer a minimal increase in the postbuckling shear strength at elevated temperatures.