MINGO COUNTY, WV - Heavy rainfall in the spring of 2009 caused landslides in numerous locations in Mingo County, West Virginia. The West Virginia Highway Department had been looking for a quick and cost-effective method to solve this kind of problem because many of the county roads are the only roads that connect important services (e.g., fire, ambulance, and police protection) and cannot be closed for long periods of time to facilitate major projects.
The May 2009 floods caused major landslides along County Route 80/1 that threatened portions of the roadway, which is the only access to dozens of houses in the village of Slabtown. After conducting the necessary research, the Highway Department decided that soil nailing would be the best method to stabilize the roadway and to minimize the amount of time the road would be restricted.
Soil nailing is a “work above project,” which works well around stream embankments because it keeps contractors from having to enter streams or wetlands to work. They can set up above the project and work down. Usually the equipment takes up one travel lane with the other lane open to facilitate traffic and emergency services. Soil nailing involves drilling holes through loose soil into an embankment at approximately a 25-degree angle and into solid rock.
Water from the June 2010 flood covered the areas that had been improved with FEMA Public Assistance Grant funding and no damage occurred. Other areas along the roadway that had not been reinforced were washed out and are being reinforced using the soil nailing method. Although this is a relatively new process being used in the State of West Virginia, it has been used in other states and countries with success.