By using the explicit solution of three-dimensional landslide stability based on modification of normal stress distribution over the slip surface
the influence of the three-dimensional end effects on the factor of safety is investigated. The three-dimensional geometry of the slip surface is assumed to consist of a cylinder and elliptical ends. The values of three-dimensional factor of safety are computed with a series of combination of geometrical parameters. The computation results show that the ratio of the 3D factor of safety to the 2D factor of safety (F3/F2) will decrease with the increase of the ratio of the width to height of sliding mass (L/H). When L/H =2
5 and 10
the maximum value of F3/F2 is 1.3
1.1 and 1.05 respectively. In addition
with the increase of the internal friction angle of the soil
F3/F2 will become smaller
that is
the three-dimensional end effect would reduce slightly.