The problem of slope stability is considered as a main geotechnical problem due to the
significant damage (material or moral) related to failure. This paper aims to study the
influence of piles on the stability of slopes loaded with strip footing a
nd investigating the
parameters affected on stability (location of pile row relative to the slope crest X , piles
spacing S , piles length L and edge distance of the footing b ). This study has been realized
in two phases : the first phase consists in establishing a numerical model for sand slope by
using finite element analyses program (FLAC3D) and determining the footing settlement at
crest of slope before using piles and after reinforcing , after that the numerical results is
compared with the experimental ones (reference case ). A close agreement between
experimental and numerical curves is noticed .The second phase deals with studying the
influence of most important parameters such as ( piles length ,piles spacing, pile row
location relative to the slope crest on stability and edge distance of the footing) on the
slope stability. The results of parametric study have shown the piles installed near the slope
crest is more efficient in reinforcing where the safety factor is increased by reducing the
distance between row of piles and slope crest and the greatest value for safety factor when
X=0.7Lx . The currently study showed the efficiency of piles to increase the ultimate
bearing capacity with increasing edge, after that at b=3B the increase in ultimate bearing
capacity decreased. Also the slope stability depends significantly on pile length and it
increases even reaching the length equals the height of the slope. At other hand, the safety
factor is reduced by increasing the piles spacing, so that the efficiency of pile is
disappeared when pile spacing equals to six times pile diameter(UBCR<1.1).