Corrugated Steel Low Profile Arch Load Rating

Recently I finished a load rating for a corrugated steel low profile arch which carries a rural road over a small brook. Unlike the recent masonry and concrete load ratings I have worked on, this load ratings was not as cumbersome. The rating criteria is much more straight forward with the codes that are currently in place. Much like the arches this structure can be analyzed using a column earth load and a live load which is distributed through the depth of the earth fill. We were able to model the live load action thru the earth fill using STAAD and creating influence lines.

The field verification inspection was very straight forward and now issues were found. The details from the plans were verified and no changes were needed. Issues that could have arose would be a flat or reverse curvature in the corrugated section which would show that the structure is either under designed, it has seen a load which was much greater than it was designed for or that the earth fill could be eroded leading to the live load not being distributed. To inspect the structure and give myself a little more practice I decided to use rope access instead of carrying down ladders through the 4 feet of snow still surrounding the bridge.