SOIL NAILING - ANALYSIS AND DESIGN

This paper describes a technique for assessing the internal stability of a soil nailed wall. The steps taken determine: (a) the position of the slip surface as realistically as possible; (b) the out of balance moment required to maintain equilibrium using characteristic material strengths; (c) the direct load and shear, for the given pattern of nails, which each nail must carry to maintain equilibrium; (d) the distribution of pressure along the length of the nail in the undisturbed zone; (e) the pull out resistance (por) under the pressure applied to each nail; (f) the permitted bearing pressures below each nail. A computer program to apply these principles has been developed by Cardiff university industry centre, and this is being extended at present. An example of a cross section to be reinforced is detailed with the relevant printout data which may be used to assist the designer in determining the nails, their number and their area.