The Job
Immediately after construction, the floor slabs settled in the cafeteria, loading dock, and kitchen of a Pittsburgh corporate headquarters. Over 12 years, the owner hired four different grouting companies to fix the issue. However, lime slurry injections were disruptive and the settlement always returned.
One contractor performed compaction grouting in a single area. While this finally stopped the settlement, the process was too invasive. The owner eventually removed the contractor after losing access to their executive dining room for nearly four months.
The Challenge
The settlement eventually reached four inches and affected nearly 20,000 square feet of flooring. To find a solution, the owner's general contractor contacted CJGeo for low-impact grouting options.
The project presented unique hurdles. Settlement impacted the entire kitchen, food prep, and dining areas, yet the facility had to remain operational. Because the building is staffed 24 hours a day, we had to eliminate dust and keep noise to a minimum. Furthermore, video inspections of the sanitary lines revealed six defects, including a 2-inch offset in a restroom drain.
The Solution
CJGeo performed 17 DCP tests to map the uncontrolled fill. We found pockets of weak soil down to 35 feet and voids up to 18 inches thick directly under the floor.
Over seven nights, our crews stabilized the site:
Void Filling: We installed 12,000 pounds of CJGrout 20SDB into immediate voids.
Compaction Grouting: We used 53,000 pounds of CJGrout 35NHV to densify soil at an average depth of 15 feet.
Our teams worked exclusively during off-hours. We started as soon as the kitchen closed and finished before the breakfast prep crews arrived at 05:00 AM. For the walk-in freezers, we completed a specialized 24-hour shift. This allowed the owner to move cold goods to reefer trailers, let us grout to 30 feet, and return the freezers to service immediately.
Through tight coordination with plumbers and floor contractors, CJGeo finished the project on time and under budget.
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