There are many soil slopes in the natural and the man-made world and the prediction of their behaviour is an important part of geotechnical engineering. Three broad types must be considered; excavated slopes or cuttings, fill slopes or embankments and natural slopes. In embankments both the fill and the foundation affect stability. Natural slopes are affected by engineering works such as impounded water, excavation or filling. In addition they may have failed already and re-activation of existing slips must be considered. The main concern when designing or analysing slopes is their stability, although in certain situations assessing likely movements is also important. This paper begins by reviewing the empirical approaches used to design early dams and embankments. It then reviews early attempts to incorporate analysis into the design process and, in particular, discusses some of the shortcomings associated with the use of limit equilibrium methods for stability analysis. The recent use of advanced numerical analysis is then discussed and examples of its use in the design of two dams described. Consideration is also given to the role of progressive failure, and its potential effect on stability is quantified by reviewing several real examples. It is shown that progressive failure can explain both deep and shallow seated delayed failures that occurred in the past in railway cuttings and which are now occurring in motorway cuttings and embankments. Finally, some remarks as to the future role of analysis in the design process are provided.
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