During an industrial facility expansion, a new blending tank needed to be installed at the top of a retaining wall. In addition concerns about lateral loading on the wall, the area is generally known to be built with uncontrolled fill over compressible soils, so settlement is a concern.
Due to the presence of industrial waste and debris in the area, light duty deep foundations such as helical piles are generally difficult to install. To avoid inducing settlement, the geotechnical EOR reached out to CJGeo for lightweight fill options to net out the increased weight of the mat foundation and blending tank.
Based on loads, CJGeo suggested a 25lb/cuft cellular grout with a compressive strength of at least 50psi. At this density, the engineer was able to balance all loads with a 4′ deep undercut. extending a few feet out around the perimeter of the tank foundation.
After the concrete foundation contractor excavated the pit, CJGeo mobilized to the site and placed 110CY of 25lb/cuft cellular concrete into the pit. The placement took less than an hour, and the foundation contractor was able to start setting steel and forms the following morning.