Developing the Centennial Yards Utility LDP 1 + 2 in Atlanta meant facing challenges from excavation to the tie-in for a project that is transforming 50 acres in the city’s downtown.

The Centennial Yards project aims to bring tenants to the neighborhood by creating a sporting and entertainment district lined by Mercedes-Benz Stadium and State Farm Arena with music venues, restaurants and 750,000 sq ft of retail space. General contractor and construction manager Ruby-Collins was responsible for the installation of approximately 1,300 linear ft (lf) of combined sewer ranging in size from 24 in. to 54 in. and the trenchless installation of 400 lf of PVC spiral wound liner (Sekisui lining) inside a 60-in. RCP pipe.

“Through interdivisional teamwork, the Ruby-Collins crews completed a difficult 54-in. tie-in inside of a 20-ft-tall junction box at the bottom of a 45-ft shaft on time and without any complications,” says Tyler Staub, project engineer.

The team finished on schedule in November 2022 and at a cost of $10.8 million with no construction-related fatalities.

Photo courtesy Ruby-Collins Inc.

Work included the installation of 620 lf of open cut pipe, a 200-lf bore under five active railroad tracks, 460 lf of 84-in. hand-mined tunnel and the installation of four shafts up to 24 ft wide and 45 ft deep. Once the sewer relocation was completed, 1,250 lf of existing sewer was abandoned in place with cellular grout and the site was restored to existing conditions.

Ruby-Collins was responsible for all field operations, with many performed in-house, including the rehabilitation of the combined sewer line without any impact on surrounding area. The firm credited the diverse expertise within its divisions to complete that work in-house, including open-cut installation by the pipe division; shafts, a jack and bore, grout abandonment and lining installation by the trenchless division; and a 20-ft-tall all junction box by the plant division. One excavation challenge involved existing conditions. The soil was contaminated and had to be treated as hazardous and couldn’t be used as backfill. Permitting was needed before it could be hauled to a landfill, and moving 10 trucks per shift prevented downtime.