A Colorado-based company that specializes in geohazard repair and prevention, GeoStabilization International was contracted by the Virginia Department of Transportation to cover about 47,500 square feet of weathered surface.
When poor drainage and a damaged culvert couldn’t handle a localized heavy rain, a bluff providing the backyard to many residential properties failed. The subsequent erosion caused a large canyon to form, the wall of which stopped within 6-feet from the back of the houses. To arrest the erosion and prevent its further spread, a slope stabilization system was needed.
Given the size of the resulting unstable earth mass below and near the house platforms and the depth of soft subsurface conditions, our solution addressed both the slope and stormwater drainage. The area below the repair area was unloaded with the construction of a shotcrete soil nail retaining system at the top of the bluff. As part of this retaining system, up to 15 feet of soil down from the current grade was removed. This soil removal reduced the slope angle below the soil nail wall system and improved the lower slope’s factor of safety. Then riprap and an engineered drainage system was installed to move future stormwater off the slope in a controlled manner.