Problem:
At a government facility in West Virginia, a burst sewer line led to the formation of a sinkhole near the structure. The sudden loss of supporting soils created unstable conditions, which posed a risk to the surrounding area and nearby infrastructure. Immediate action was required to stabilize the affected soils and prevent further deterioration, particularly with the potential for continued water migration toward the building.
Solution:
USG was engaged to remediate the sinkhole and address the underlying cause of the soil instability. Due to the sensitive nature of the facility, all USG personnel completed required background checks prior to mobilization, ensuring compliance with site-specific security protocols. The project was completed in two phases.
In the first phase, polyurethane injection was used to stabilize the sinkhole. The expanding material filled voids and densified the surrounding soils, restoring support in the affected area. Following this stabilization effort, another contractor completed backfilling operations to restore surface conditions.
The second phase focused on preventing future soil raveling toward the structure. USG created a grout curtain wall using polyurethane injection to create a barrier within the soil. Steel rods were driven approximately 30 feet into the ground to deliver the material at depth, allowing for targeted treatment along the path of potential water intrusion and strengthening of weak soil zones from the previous sinkhole. Shoring was utilized throughout the process and adjusted as needed to maintain safe working conditions during installation.
Results:
The polyurethane injections successfully stabilized the sinkhole and restored the integrity of the surrounding soils. The installation of the grout curtain wall effectively limited further raveling of the soil toward the building, addressing the root cause of the initial failure.
With both stabilization and water control measures in place, the site was returned to a safer, more stable condition. The phased approach allowed the issue to be resolved efficiently while meeting the operational and security requirements of the facility.
