In the winter of 2015, a private neighborhood in Madison was preparing for a new phase of expansive development that would include a man-made canal leading directly into the Ross Barnett Reservoir, a 33,000-acre lake in the Pearl River Valley.

To connect the new development with the existing neighborhood, a bridge was designed to cross over the canal. Supporting the bridge would be abutment walls with wing wall sections to support the embankments leading up to the bridge. The general contractor at Lost Rabbit contacted MMC Materials, local Redi-Rock supplier in Jackson, to determine if the Redi-Rock system could provide a cost-effective solution for the wing wall sections.

Partnering with MMC Materials, JC Hines & Associates began analysis on the site conditions, discovering highly expansive clay soils with low shear strength. Given the height of the wing walls, the design team at JC Hines & Associates determined that Redi-Rock’s Positive Connection (PC) system would be the safest and most efficient option.

The PC system uses 12-inch-wide strips of geogrid reinforcement to anchor each block unit in the reinforced backfill zone. As a mechanically stabilized earth (MSE) wall system, the reinforced zone was backfilled with a coarse sand fill to provide sufficient shear strength for the wall and allow adequate drainage. Mitigating the effects of the expansive clay soil was a critical design parameter, so the wall structures were placed on a reinforced concrete foundation supported by soldier piles.

Installation moved quickly – the entire bridge system was completed in under 30 days.