Stability of Earth Slopes

This chapter examines the stability of earth slopes in two-dimensional space using a limit equilibrium method. Figures 9.1(a) and 9.1(b) illustrate a rotational failure where a mass of soil rotates on a circular or non-circular failure surface at its limit state. In the presence of a hard layer, a combined translational and rotational failure could occur ( Figure 9.1(c) ). An infinite slope is normally associated with a translational failure parallel to the ground surface ( Figure 9.1(d) ). The failure of a reinforced slope, however, is rather different and is idealized either by a combination of wedges (Department of Transport UK, 1994 ) or by a circular failure surface ( Koerner & Robins, 1986 ; Koerner, 1994 ).