Leveling Existing 45,000 sq. ft. Concrete Slab of Commercial Building in South Orange County, CA.

Challenge

In March of 2011, Saber was contacted to inspect and give recommendations to level an existing concrete slab at a 45,000 sq. ft. commercial building in South Orange County, CA.  This slab had been experiencing settlement due to voids created by settlement of the underlying soils. A previous repair was completed in 2008, utilizing a cementitious grout injection beneath the slab. The soil was then overburdened due to the weight of the grout at 150 lbs. per cubic foot. Saber determined that the existing slab had settled a further 2.75”.  There were two options for repair that were discussed; coring into the existing slab and installing helical piers to a load bearing soil stratum, or injection of polyurethane resin below the concrete slab to fill all voids, raise the concrete slab back to the original elevation while also compacting the underlying soil.