When a fire sprinkler main ruptured at a 165,000 square foot warehouse facility, slab cracks, erosion of the base material under the slab, and severe damage to architectural finishes in the office areas resulted because the break occurred over the weekend when no one was present. It was not discovered until the following business day.
When a warehouse slab is lifted by water, it does not always settle back into its original position because the water often transports the soil to new areas, leaving voids under the slab where the slab in no longer in full contact with soil. In a warehouse, these voids can become a problem due to the cyclic loading on the slab caused by heavy forklift traffic.
We performed a relative elevation survey to view the relative levelness of the warehouse slab followed by Ground Penetrating Radar (GPR) to determine the extent of the voids and loss of subgrade support under the slab. Based upon the testing performed, we developed repair recommendations to restore the integrity of the floor slab.