ABSTRACT
All slopes have a tendency to move, some more than others. Such movements can vary in origin and magnitude, and range from near-surface disturbances of weathered zones to deep-seated displacements of large rock masses. The stability of slopes is an important consideration in the design of man-made excavations such as those for an open-cast mine, a quarry, a road cutting, a large foundation or a deep trench. Natural slopes become unstable as a normal phase in slope erosion and the stability of slopes forming coastal and river cliffs, valley sides, especially where forming reservoir margins, and dam abutments, may have to be assessed if their movement endangers the public or engineering structures. Slope movement and failure can occur in several ways which may operate either separately or together. Analyses for slope stability can determine: the conditions under which movement will commence, and the amount of deformation that occurs under given conditions.
