The currently available literature relevant to the use of spaced piles to stabilise embankment and cutting slopes is reviewed. The report focuses on instrumented case history studies, analogies with other construction forms where soil flow and arching occurs, and summarises the current design methods available when using this technique. The use of a single row of piles is likely to be an effective construction technique for the permanent reinstatement and repair of both unstable and failed slopes. On the highway network, many slopes which are prone to shallow failures are now reaching a critical age for deep seated failure to occur. In addition, prolonged delays in dealing with shallow failures may lead to the formation of deeper slip. Determination of pile diameter, spacing, penetration depth and optimum location on the slope is however a complex soil-structure interaction problem on which there is currently little design guidance. This review seeks to give designers some guidance on the various issues involved. (A)
Abstract