By Big R Bridge
A custom low profile box culvert geometry was used for one crossing. Because of the low profile and required hydraulic area, a multi-cell concrete box was the only other option. That option was discarded because of cost – a deep corrugated Buried Bridge was the only option left that could bring the project in budget. The structure was assembled by an inexperienced crew in just 5 days.
The arch structure was bid directly against a smaller concrete box alternative – a 18’ span x 11’ rise 4-sided box. The total installed cost of the deep corrugated steel Buried Bridge was lower in every contractor’s bid, with the average cost savings being around 20%. In addition to that the concrete box option was cast-in-place and involved excavating and grading the channel, which would have been detrimental to the project schedule. The deep corrugated steel Buried Bridge was assembled in 3 days by an inexperienced crew.
Using deep corrugated steel Buried Bridges for both crossings was the only way to make the owner’s budget work and the time savings compared to traditional concrete box culvert options helped the contractor keep the project on schedule so that the start of school in the fall was not impacted.
The steel Buried Bridges also allowed for a natural stream bottom, which was desirable from a sustainability standpoint.