The slope adjacent to the athletic fields at Saint Mark Catholic School in Huntersville, North Carolina had been experiencing severe surface erosion and shallow/surface failures.
Engineers decided to pursue a solution that involved driven soil anchors and a turf reinforcement mat for veneer stability. Fortrac® 3D from HUESKER was chosen as the ideal fit for the turf reinforcement because of its high tensile strength at low elongations. Fortrac® 3D’s unique three-dimensional construction and high tenacity differentiate it from other turf reinforcement mats. Unlike other products that elongate as much as 65%, Fortrac® 3D has a maximum elongation of 12%, which means it keeps soil in place. Uretek ICR performed the slope preparation and repair, installing the Platipus anchors and Fortrac® 3D.
Project Execution
The plan for repair of the athletic field slope consisted of installation of slope reinforcement and erosion control measures. After all existing vegetation and unsuitable soil was stripped, the slope was re-graded to a 2 horizontal: 1 vertical slope. A 12-inch berm was also constructed at the top of the slope and catch basins with slope drains to help divert site runoff from eroding the repaired slope. Surface/slope reinforcement materials were then installed to prevent further surface erosion and surficial slope failures.
The stabilization and reinforcement materials consisted of the Platipus driven anchor system with Fortrac® 3D turf reinforcement mat. Installation of Fortrac® 3D is easy. After the slope surface has been prepared and seeded, Fortrac® 3D was anchored at the top of the slope. Then, Fortrac® 3D is simply unrolled down the face of the slope. Platipus soil anchors were then installed by Uretek, eliminating the need to pin the Fortrac® 3D.
Conclusion
The project was completed in the spring of 2010. The athletic field slope that had been failing was restored and Saint Mark Catholic School was able to continue using the field without fear of continued slope failures. The slope was reseeded at the completion of the project, and several weeks later, Fortrac® 3D had promoted full vegetation of the slope.
Product Description
Fortrac® 3D is a flexible, three-dimensional reinforcement grid made from high tenacity, low creep polyester with the additional function of protection against soil erosion. A special polymeric coating provides protection against ultraviolet degradation and mechanical damage. As a high tenacity geogrid, Fortrac® 3D provides an ideal reinforcement against soil slippage on the slope. Through its structure, Fortrac® 3D improves the soil retention on a vulnerable slip plane surface and its tensile strength carries the loading forces imposed on the anchorage zone. The surface stability of the structure is increased, resulting in a safer and more economical construction method.
Fortrac® 3D is available in several strengths, from 30 kN/m to 120 kN/m, offering a comprehensive product range. The flexibility, robustness, and simple installation of Fortrac® 3D ensure a successful end result.
Product: Fortrac® 3D-30
Owner: Saint Mark Catholic Church
Engineer: ECS Carolinas
Contractor: Uretek ICR, Mid-Atlantic
Learn more about Fortrac® 3D at:
http://www.huesker.com/usa/geosynthetics/products/fortrac-3dr/
Learn more about Huesker at:
http://www.huesker.com/usa