Civil Engineering Association

The paper presents a critical review of the state of the art of geotechnical engineering of natural slopes, cuts and fills in soil. Topics which are covered include the pre and post failure mechanics at the micro and macro scale, including discussion of contractant and other strain weakening soils, creep, progressive and retrogressive failure and fissured clays. Geotechnical investigation requirements and methods for analysis of stability and deformations, and for analysis of post failure velocity and travel distance are reviewed. It is concluded that many slope instability hazards may be managed by traditional factor of safety methods, but that it is important that the post failure behaviour be considered. Observational, and risk assessment methods may be more appropriate than the traditional methods in many cases.