Concord Road Covered Bridge

Smyrna, GA – Nickajack Creek

Problem

The Concord Covered Bridge is a Nationally Registered Historic Place on a very active traffic corridor in Smyrna, GA. The bridge was originally constructed around the mid 1800’s. Over the years, the bridge remained the same, while traffic increased in both volume and size. With a mere 7-foot height restriction, the bridge was repeatedly exposed to vehicle strikes by large trucks and trailers. In 2009, Cobb County DOT installed steel “headache beams” at either end of the bridge in an effort to keep over-height vehicles from striking the covered bridge. Unfortunately, the “headache beams” were not completely effective in ceasing the bridge strikes, with an average of one vehicle a month impacting the covered portion of the bridge. By 2016, the bridge was leaning significantly from the years of vehicle strikes.

Solution

Cobb County DOT contracted with Suncoast to carry out the restoration plans developed by Arcadis. The plans included installing an additional steel H-Pile, cleaning and recoating the 8 I-beams that had been previously installed under the bridge deck for support, stabilizing the bridge deck by welding and bolting diaphragms between the beams, installing a series of steel “boxes” within the covered bridge for additional support, straightening the leaning covered portion, removing and replacing the board and batten siding, and removing and replacing the cedar shake roof.

Results

After four weeks of prep work, the bridge was straightened in about 15 minutes. At the start of the project, the bridge was out of plumb almost 12 inches. Once straightened, it was only out of plumb less than ¼” over the 133’ length of the bridge. All of the supplemental steel placed inside the bridge for support was camouflaged with paint to blend in with the wooden structure. Once repairs were complete, the bridge received a fire and graffiti retardant sealer. The historical marker was also reinstalled at the small parking area. The project was completed on time and on budget without any issues. Suncoast worked diligently with Cobb County DOT, Arcadis, and the local “Friends of the Covered Bridge” historical society to ensure the bridge could be enjoyed for many more years. This bridge remains one of the busiest covered bridges in the southeast with a traffic count estimated at 10,000 cars per day.

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