Project DetailsLocation: Atlanta, Georgia
Owner: City of Atlanta
Contractor: Georgia Bridge and Concrete, LLC
Precaster: The Reinforced Earth Company
Products Used- Reinforced Earth®
Opened in time for Super Bowl LIII, this bridge provides a safe passage over Northside Drive, connecting pedestrians to Mercedes-Benz Stadium, a MARTA station, parking, and the surrounding neighborhoods in downtown Atlanta.
Both ends of the bridge utilize a narrow back-to-back Reinforced Earth® mechanically stabilized earth wall as a 15-foot wide curved ramp up to the bridge deck. The concrete MSE wall panels include a diamond pattern, which along with the curved alignment, contributes to the Architect’s serpentine design theme of the overall structure. Shadows during the day, and LED lighting at night further enhance the look of the bridge.
Shadows during the day, and LED lighting at night further enhance the look of the bridge.
The MSE walls reach a height of 37 feet tall including embedment, and a height of 21 feet in the back-to-back sections. In a back-to-back MSE wall design, the soil reinforcements on either side overlap a minimum distance in the middle of the volume, providing stability that allows the structure’s base-width to be reduced below the typical 0.7xH. The horizontal alignment of the ramps are compound curves, with the wall face on radii as small as 40 feet.
Vertical staged construction of portions of the ramp, with a 30-day waiting period, helped the engineer to verify the bearing capacity of the foundation. The majority of the MSE wall fill volume was crushed stone, however a length of the ramp that spanned a MARTA tunnel required a light-weight alternative. In this area, the wall design incorporated geofoam with a unit weight of 2 pcf, as opposed to the 100 pcf crushed stone.