Winston Salem State University Slope Stabilisation, USA
To provide much-needed access to two remote parking lots at Winston Salem State University, a bridge was built to cross an existing rail line and connect the lots to the main campus. The owner of the railroad, Norfolk Southern, would not allow the newly built bridge to be accessed until an adjacent abutment that had begun to slough was reinforced. The railroad felt there was a risk that the vibrations caused by passing trains could lead to a shallow plane failure.
The Platipus ARGS® (Anchor Reinforced Grid Solutions) system was specified by a local Geotechnical Engineer who was very experienced in the local geology of the Piedmont region. Summit Design and Engineering performed a global stability analysis and concluded that the depth of failure was between 5 –10 feet deep. The design included a grid patterned of 2 TN anchors driven to a minimum depth of 15′ and pre-tensioned to 2,000 lbs. After all the anchors were loaded, the slope was covered in a 4” thick reinforced concrete face. The anchors were subsequently tensioned one last time to the concrete face once it had cured.