In North Yorkshire, U.K., 20 months of work has been completed by Balfour Beatty on a $21 million (£16 million) scheme to stabilize the cliff between Scarborough Spa and the Esplanade on Scarborough’s South Cliff.
The South Cliff Slope Stabilization Scheme involved piling along the rear of the spa complex with almost horizontal drainage to address the deep-seated failure of the slope, soil reinforcement (nailing), and re-grading of the slope to address shallow and medium-seated instabilities.
Utilization of the Presto GEOWEB Geocell Soil Retention System, along with the patented ATRA Tendon Clip (ATC) system, helped to achieve revegetation, protection from soil erosion, and covering of most of the 4,585 soil reinforcement nails. The 5.9-inch (150-mm) GEOWEB cells were secured to the slope without the requirement for pins or anchors, ensuring a fast and safe installation method for the CAN Ltd. installers on slopes up to 60 degrees.
CAN Ltd. placed more than 3,600 tons of topsoil into the cells, then sprayed the area with grass seed via hydroseeding. The complex engineering scheme, project managed by Royal Haskoning DHV, and carried out by contractor Balfour Beatty on behalf of Scarborough Borough Council, has resulted in the “protection of 380 homes and 38 key businesses with a combined value of $152 million (£114 million).”
The GEOWEB 3D Slope Protection System provides a structurally stable environment for topsoil and sustainable vegetation through a structured network of interconnected cells. The 3D GEOWEB system confines and reinforces the vegetated upper soil layer, increasing its resistance to erosive and sliding forces.
By pairing the GEOWEB system with ATRA Tendon Clips (ATC), it allows for an easier installation of the high-density polyethylene (HDPE) GEOWEB system off-slopes. The ATCs are high-strength load transfer devices designed with twice the pull-through strength of any other load transfer devices—creating the most secure geocell connection.