In October 2019, in Ooltewah, Tennessee, truck drivers at a new FedEx distribution center were struggling with settled pavement and unsafe driving conditions as they approached and exited the facility along the main entrance driveway. With construction of the new facility completed in 2017, the client knew that the problem was not age-related. Shortly upon completion of the new facility, the settlement issues had begun to appear. In fact, by the time URETEK was contacted, the customer had already tried to have the entrance driveway issues corrected…twice.
URETEK crews consulted with the FedEx and reviewed an existing geotechnical analysis that indicated surface water drainage issues were concentrating and negatively impacting poor soils below the surface. URETEK crews determined that URETEK Deep Injection® (UDI) would provide an ideal solution for the ongoing weak soil issues, and that all work could be completed without interrupting the owner’s normal business. URETEK consulted with the civil engineers to provide budgets, injection plans, specifications, and schedule input. A design package was put out to bid by FedEx based on URETEK’s specifications. URETEK won the polyurethane grout scope of the project in a competitive bidding situation.
Because of the nature of the customer’s business, URETEK designed an injection grid and work schedule that would have the least impact on operations at the facility. As work began, crews performed UDI into soils supporting the problematic areas to stiffen, compact, and reduce the permeability of the soil mass. Dynamic Cone Penetrometer (DCP) testing was performed by URETEK’s crew to confirm and adjust the design. In some areas, additional depths of injection were required to properly treat the soils. Concurrent with URETEK’s work, other contractors addressed the surface water drainage issues present at the site and completed asphalt mill and overlay work.
Over three weeks, URETEK crews worked with other contractors to successfully stabilize the soils in the problem areas at the FedEx distribution center. Work was coordinated with the customer to avoid heavy traffic times and to maintain the steady flow of trucks. With deep-soil stabilization work complete, managers at the FedEx facility in Ooltewah were at last able to consider their new facility “finished” and ready for smooth operations.
URETEK Deep Injection® (UDI)
Widely referenced throughout our industry, UDI involves the injection of structural polymer into base and subgrade soils to increase the load bearing capacity. This is achieved by injecting the polymer through small holes drilled directly through the pavement structure to depths determined by site-specific analysis. Our URETEK 486 Star® material flows easily into voids and weak zones within the soil mass below. Through a controlled chemical reaction, the expanding polymer compacts surrounding soils and applies a controlled pressure on targeted areas of the affected pavement above. If needed, a multi-injection design plan is utilized to gently return the pavement to its original grade. The composite material quickly cures into a strong, dimensionally stable, and water-resistant geo-material, providing years of reliable service.
URETEK 486 Star®
URETEK 486 Star® polymer is a two-component, high-density, expanding thermoset polyurethane system. It was developed to be the ideal solution for under-sealing, void filling, lifting of settled pavement, stabilization and stiffening of weak soils, and for encapsulating and sealing buried infrastructure. URETEK 486 Star® is environmentally inert, non-toxic, and resists underground water erosion or weakening due to its industry-leading hydrophobic properties.