The Front Range area of Denver has a tremendous amount of expansive soils know as bentonite, a soil that contains a high percentage of clay that can absorb vast quantities of water.
This can cause the soil to expand and shrink up to 10% depending on the weather conditions. Prior to Hoar’s involvement with the project, the geotechnical and structural engineers prepared a deep foundation design using a structural slab supported on-grade beams. During preconstruction, we challenged the engineers to investigate alternate solutions for addressing the expansive clays. With the help of a local site work subcontractor and our preconstruction efforts, the structural and geotechnical engineers designed a more cost effective solution. The engineers determined that we could undercut the site 11 feet and moisture condition or “pre-swell” the soils. The allowed us to use a shallow foundation system that ultimately saved the owner over $400,000.
Boulder Associates, Inc.