Faced with unexplained cracking and movement of a warehouse slab, the Owner decided to do some investigation. The tenant was becoming increasingly concerned because the floor slope near the tilt-wall panel reached the point that stacked pallets to become unstable and overturn.
Our investigation included an elevation survey of the distressed area, followed by Ground Penetrating Radar (GPR) to investigate sub-surface conditions. The elevation survey showed that as much as 5 inches of movement had occurred. The GPR showed that the steel reinforcement was often misplaced, and that apparent subsurface voids existed.
During testing, it was also discovered that the main faulting crack occurred at the termination of tilt-wall panel dowels connecting to the slab. The rotation of the slab also caused distress at the tilt-wall panel connection. Since the cracking occurred at the end of the wall panel dowels, the wall was in danger of moving because the wall was not longer properly tied into the floor slab. Based on the findings, we made repair recommendations.