Location: Charlotte, NC Overview: The Four09 Queens project involved the placement of a lightweight engineered backfill to support foundation construction within a tight urban site. The work was performed to address lateral earth pressures between the permanent foundation wall and temporary lagging wall during building construction. Challenge: Limited access and close spacing between the foundation wall and lagging wall created constraints that made conventional backfill impractical. The material selected needed to minimize lateral earth pressures while allowing for efficient placement within the narrow excavation and maintaining schedule requirements. Solution: Low-Density Cellular Concrete (LDCC), manufactured by Elastizell, was selected due to its low unit weight, flowability, and controlled placement characteristics. RyanGeo placed 200 cubic yards of LDCC in a single 5-foot lift between the foundation wall and the lagging wall, providing uniform support while reducing lateral pressures on the permanent structure. Results: • Total Volume Placed: 200 cubic yards • Placement Configuration: 5-foot lift between foundation wall and lagging wall 300LF