Maple Ridge Wind Farm

The Maple Ridge Wind Farm, projected to be the largest wind farm east of the Mississippi River, was on a tight schedule and had run into a major problem. Over twenty-three miles of access roads were needed in order to build 120 wind turbines in the project’s 1st Phase. A Tensar distributor was contacted by the project’s contractor to help assess soil conditions under the proposed access roads. The contractor needed a fast solution as conditions were unfavorable.

The original tower access road design included an undercut of approximately 10 inches, inclusion of a geotextile and the installation of close to 10 inches of aggregate. The original width of the access roads was 16 feet. Several areas were observed where silt and clay had day-lighted at the surface (indicating that the geotextile had ruptured or failed) due to rutting. The geotextile was also noticed in places at the ground surface. “Rocking” (a 1-to-2 inch deflection or movement of the aggregate by standing and rocking back and forth) was also detected. Soft to medium soils were found with an estimated CBR of approximately 0.8 to 1.6 – based on observed rutting depths of vehicle tracks. The original solution, which included a geotextile, had failed under heavy traffic.

Tensar geogrids were successfully used at the site to improve the bearing capacity of the soils, reduce the amount of aggregate required to stabilize the soils underlying the tower access roads and provide ease of construction. This allowed the high-profile project to stay on track and on time, while providing Lowville and its surrounding areas with a new source of power.