URETEK Rapid Pier System for Slope Repair in Texas

Problem

The Skylar Apartments in Clear Lake City, Texas, are adjacent to a channel (Harris County Flood Control District Unit Number A107-00-00). The apartments are separated from the channel with a slope, but a 200-foot by 60-foot portion of this slope was failing. As the slope failure progressed, encroachment on the apartment buildings became an imminent concern. URETEK developed a solution to re-form the slope and stabilize the soils. The goal of the project was to repair the slope so that its appearance would match existing adjacent slopes not impacted by the failure, and to ensure the future stability of the slope.

Analysis

The slope failure was so severe that URETEK determined they would need to first create stable zones at the top and the toe of the slope before they could regrade and repair it. URETEK planned to use custom URETEK Rapid Piers (URPs) to stabilize the slope.

Solution

URPs are created by first placing perforated pipes filled with aggregate into shafts in the soil. The filled pipes are then injected with a patented, high-density, two-component structural polymer. The polymer exiting through the perforations binds the pier to the surrounding soil. The polymer that remains in the pipe cures to create a strong core for the pier. Once the URPs were installed, URETEK made additional polymer injections into the soil to interconnect the URP units into a pier group. These “tie-in” injections and the resulting pier groups produced greater strength and stability in the soil system. Upon completion of the injections, the slope was graded with top soil to ensure the URPs remained several feet below grade and to match existing sections of slope. Finally, a Hydraulic Erosion Mat was installed to restore the pre-failure appearance and prevent future erosion.

Result

URETEK successfully stabilized the slope from top to toe and restored the slope to its pre-failure grading and appearance. The use of URPs and a Hydraulic Erosion Mat ensured the job was completed quickly while also providing long-lasting stability for the slope. The slope has been inspected periodically since construction, and no movement or erosion has been observed to date. URETEK delivered a fast, effective, and long-lasting solution for the Skylar Apartment complex.

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.

Slope Repair
Slope Repair
The damaged slope before repairs
Slope Repair
URPs are injected with polymer individually and as a group to create a strong, interconnected system