Corrugated Steel Ellipse Culvert Response: Experimental Results Compared to Design Approaches

Design methods for corrugated steel culverts in current design standards consider the circumferential force in culvert walls (i.e., hoop thrust) to be the dominant load-carrying mechanism in these structures. However, recent studies have shown that bending moment, rather than thrust, is often the more dominant response for corrugated steel culverts under shallow burial conditions and vehicle loading. In addition, 2D finite element analyses have historically been unable to effectively capture the effects of discrete surface loads, such as wheel loads, on the response of buried metal culverts. To investigate these issues, the bending moment and thrust responses from an experiment involving an elliptical corrugated steel culvert under shallow burial conditions and simulated vehicle loading are compared with the bending moment and thrust estimates from the Canadian bridge design code and CANDE-2019 (a commonly used public domain finite element software package) and the thrust estimates from the American AASHTO LRFD bridge design code (which does not consider moment directly). The comparisons show that the Canadian code and CANDE-2019 models with a fine mesh and the continuous load scaling elasticity-based method appear to be the most effective for the investigated culvert and loading, while there is a need to modify the American AASHTO LRFD code to consider moment more directly. In addition, the results suggest that, under these conditions, the current approaches for estimating the peak bending moment response are more effective compared with the approaches for estimating the peak thrust response.