Parametric study of the stability of slopes reinforced with piles

This paper analyses the stability of a two-layers slope reinforced with a row of piles. The theory of Poulos (1973, 1995) is used to evaluate the pile response to a uniform lateral free-field displacement. A parametric study is carried out in terms of the ratio between the safety factor of the reinforced slope to the safety factor of the slope without piles, by varying geometric and mechanical dimensionless factors. For different shear strength of the soil a range of pile position is found, at which the piles offer the maximum contribution to slope stability. The length of piles is found to slightly influence the safety factor. The results also indicate that the critical slip surfaces do not always intersect the piles and that the thickness of the shallow layer can significantly influence the effectiveness of the passive piles.