Measured Responses of a Corrugated Steel Ellipse Culvert at Different Cover Depths

Typical design and installation methods for corrugated steel culverts involve consideration of a minimum burial depth and most current North American design codes consider failure only due to excessive circumferential force in the conduit walls (i.e., hoop thrust). However, recent studies have shown that the bending moment is often the more dominant behavior for corrugated steel culverts at shallow cover. To address this issue, an elliptical corrugated steel culvert was tested under simulated vehicle loading at depths ranging from 0.1 to 1.2 m. The results show that, under a wheel pair load, a peak negative bending moment, and thrust, force is consistently developed at the crown with positive bending moments adjacent to the crown and near the shoulders. When the flexural and circumferential force results are extrapolated to the yield point and compared, the bending moment values are up to five times larger than the yield limit while thrust values are only 60% of the limit. The test results suggest that bending moments should be considered during the design and installation of corrugated steel culverts at shallow cover.