Report No. : GEO Report No. 251

Report Title : Study on Nail Head-Ground Interaction Using Numerical Modelling (2010), 133 p.

Author : S.P.Y. Cheung & C.H.W. Chan

Abstract

A study using numerical modelling has been carried out to investigate the nail-ground interaction in a soil nailed slope. The effects of soil nails in stabilizing a slope have been examined by restraining the deformation of the soil nail heads. No soil nail elements were put in the model, which avoid the presence of a continuous steel 'plate' and the soil could theoretically move downward between the steel bars. This numerical model is different from other two-dimensional analysis assuming steel bars in plane strain conditions but it gives an upper bound solution of the confinement effect of the soil nail heads.

The results of the study have revealed that the confinement effect behind the soil nail heads increases the mean effective stress and the forces acting behind the soil nail head are not directly proportional to its size. In particular, the relative displacement between the soil mass and the soil nail head in gentle slope is found to be mainly in parallel direction to the slope surface. In light of this, a soil nail head with a steeper face intercepting the relative displacement would be more effective in mobilising axial force in the soil nail and new details have been developed.

Download Document(s)