Local buckling analysis of trapezoidal rib orthotropic bridge deck systems

Abstract

This paper compares the behavior of local buckling in trapezoidal rib orthotropic bridge deck systems. The primary objective of this paper is to compare the condition of a uniform stress pattern (column) and that of a non-uniform stress pattern (beam-column). The former is current practice while the latter is recommended based on the current study. The presence of thin steel plate members within the deck system causes local buckling to be a valid concern. Parametric analyses were performed using the finite element method to compare local buckling of the rib walls (webs) and deck plate by varying the corresponding width-to-thickness ratios. Since the rib walls have the highest width-to-thickness ratio, they were the primary focus of this research. Generally, this type of deck system is analyzed under axial compression due to global forces. However, bending moments from the local loading of the deck weight and vehicles are typically present in the system. Therefore, the bridge deck system was analyzed under axial compression and negative bending moment for local buckling in the rib walls. The results demonstrate a reduction in the capacity of the deck system at which local buckling is initiated in the rib walls due to the existence of negative bending moment near the floorbeams in addition to the global axial forces.