Stability determination for layered soil slopes using the upper bound limit analysis

By using the upper bound limit analysis, a method has been proposed in this article to compute stability numbers for layered soil slopes. The rupture surface was assumed to be a combination of different logarithmic spiral arcs with a common focus. The analysis ensures the kinematic admissibility of the collapse mechanism with respect to the rigid rotation of the bounded soil mass about the focus of the logarithmic spiral. For the sake of illustration, the computations, however, were exclusively performed only for a two layered soil slope. The effect of the pore water pressure and horizontal earthquake body forces was also incorporated in the computations. The computational procedure was validated by making a comparison of the obtained stability numbers with those reported in literature.