Tackling a 14-foot Drop with Geofoam Backfill

On the Safe and Welcoming Entrance project, the biggest challenge the team had to tackle was grading the site—which had a 14-foot drop along the east side of the building. The architects and structural engineers at TKDA created a plan to utilize geofoam backfill and engaged TR Concrete to install it.

Geofoam is a lightweight fill material that reduces the ground load and minimizes settlement. On an addition project like at Anthony Middle School, where traditional fill materials such as soil and rock, would be heavy, geofoam mitigates the need for structural steel support and uses less concrete. It is also easy to install.

“We installed approximately 4,500 cubic feet of geofoam at Anthony Middle School,” said Randy Becker, President of TR Concrete. “Geofoam is easy to handle and quick to install. Its lightweight nature makes it easy to cut, shape, and position.”

Despite how lightweight it is, geofoam has excellent load distribution properties, minimizes differential settlement, and provides consistent support across construction areas. It is not susceptible to erosion or decay and has long-term stability.

“Geofoam is also environmentally friendly,” said superintendent Brian Hillestad of Stahl Construction. “It is made of recycled material, contributing to sustainable construction practices. It also helps with insulation, trapping hot and cold air, helping to control temperatures at the building foundations.”

The result was a shorter schedule, less concrete, and a more stable construction for Anthony Middle School’s addition.