Soil mechanics and natural slope stability

This chapter discusses the study of slopes in the context of soil mechanics and mass movement processes. The term 'soil' is throughout used in the engineering sense, that is, to refer to the regolith or loose detrital material on any hillslope. Slopes composed of granular soils have high enough permeabilities for long-term equilibrium pore pressures to be reached so rapidly that short-term conditions never apply, even under rapid excavation. Chandler identified several important principles relating to long-term stability of natural clay slopes in studies of failures in the Lias Clay in Northamptonshire. Soil mechanical principles were applied to slopes over relatively large areas and, when used sensibly, satisfactorily explained the limiting stability of a range of slopes. Rouse extended the application of soil mechanical approaches to studies of slope stability in the valleys of West Glamorgan, South Wales.