The technique of soil nailing represents a promising method of improving the stability of existing or newly constructed earthwork slopes. Research on this topic is in progress, but there is presently no generally accepted design method, and little information is available to UK engineers on possible applications. The technique has, however, been used in France for a number of years. The Laboratoire Central des Ponts et Chaussees (LCPC) is engaged on a national research project (CLOUTERRE) on this subject, and has published a number of articles in their journal, 'Bulletin de Liaison des Laboratoires des Ponts et Chaussees'. As part of the programme of co-operation between the Ground Engineering Division of the Transport and Road Research Laboratory (TRRL) and the Soils Division of LCPC, TRRL is publishing edited translations of several papers on soil nailing. This Report is an edited translation of the second of these papers, by Marchal (1986) (see IRRD 119226). It describes a laboratory study of both rigid and flexible single nails embedded in sand in a 600mm diameter shear box. The results confirmed that there is an optimum angle for the nail relative to the shear plane; that displacements in reinforced soil are very different to those in soil alone; and that there is a marked difference in the behaviour of rigid and flexible nails, greatest benefit being obtained from flexible nails within the range tested. Other conclusions were that existing methods of determining soil-nail interaction were not satisfactory. (A)

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