By: Contech Engineered Solutions
This low profile structural plate arch is located in Rockingham County, Virginia. It was constructed in 1979 as a replacement of a deteriorated, single-span steel truss bridge. VDOT obtained Right of Way upstream of the existing bridge to construct the 33′-2″ x 11′-1″ structural plate Low Profile Arch and built it while the old bridge was still in service. Upon completion of the new bridge, the roadway was realigned to carry two lanes of traffic over the new steel arch and the old truss bridge was subsequently dismantled.
The arch bears on reinforced concrete footings that were constructed on a rock subgrade. It is 104’ long and step-beveled on both ends. The bevels are reinforced by concrete slope collars. The structure is under 4-5 feet of fill and incorporates the reinforced concrete thrust blocks characteristic of structural plate arches.
After over 42 years in service, the arch is still in excellent condition. The shape is extremely uniform and stable at the end treatments with no signs of settlement or deflection. The structure is inspected on a biannual basis and the current condition rating is a 7 (good). The latest inspection report only mentions scattered efflorescence at plate arch seams and bolts.
The project is a testament to the durability of structural plate, properly constructed.