Study on Slope Stabilization by Soil Nailing

Abstract

Since its development in Europe in the early 1970s, soil nailing has become a widely accepted method of providing temporary and permanent earth support, underpinning and slope stabilization on many civil projects in the United States. In the early years, soil nailing was typically performed only on projects where specialty geotechnical contractors offered it as an alternate to other, conventional systems. More recently, soil nailing has been specified as the system of choice due to its overall acceptance and effectiveness. However, although the theoretical engineering aspects of soil nailing may be well understood, there is a far lesser degree of understanding, even within the geotechnical community, as to the site conditions – where ,when and why – under which soil nailing should, and should not, be used. The purpose of this paper, therefore, is to offer experienced-based guidelines to owners, engineers, designers and general contractors trying to decide if soil nailing is the right system for their project. Typical soil nail details, procedures, design, monitoring and testing considerations, and case studies are presented as a tool to aid in making those decisions A landslide stabilization system using tiered soil nail walls and a mechanically stabilized earth (MSE) wall was instrumented and monitored to evaluate overall unstable slopes. Site conditions, design aspects, and construction of the soil nail and MSE walls are described. Performance based on field observations of ground movements and load transfer in soil nails is described and discussed. Recommendations for applying soil nail walls to slope stabilization are presented performance and facilitate comparisons between design assumptions and field observations. This project demonstrates the feasibility of utilizing soil nail walls for stabilization of active landslides, extending the application of soil nailing beyond its traditional scope of stabilization of cut slopes or for potentially