Slope stability. Geotechnical engineerng and geomorphology / Устойчивость склонов. Инженерно-геологические изыскания и геоморфология

Problems of slope stability, instability, and the associated mass movement processes of slope failure, represent research themes common to both geotechnical engineers and geomorphologists, although their perspectives clearly differ. While the engineering concern is generally site specific and limited by project design-life considerations to time periods of less than 100 years, for the geomorphologist longer term slope stability and slope evolution, involving a mixture of slope processes operating over tens of thousands of years, constitute a major area of enquiry (e.g. Kirkby, 1984). This simple distinction in terms of time-scale is, however, complicated by additional concerns. For engineers, the practical problems arising when fossil shears are reactivated by natural or artificial disturbances place a premium on understanding the history of slope development over geological (late Quaternary) time-scales, as the emphasis of the collection of studies introduced by Skempton (1976) illustrates. On the other hand, geomorphologists are necessarily interested in the process mechanisms preceding and during failure, in the types of mass movement process involved and the translation of debris. The apparent dichotomy in terms of time-scale is thus largely an illusion, and the true distinction lies in the objectives of analysis of slope stability: a statement of the stability of a specific slope for the engineer, and an appraisal of the role of slope failure processes in slope evolution for the geomorphologist. Given, therefore, that it is the objective rather than the methodology that distinguishes engineering and geomorphological approaches, there should be much to gain from a recognition of the common ground and potential for collaboration between engineers and geomorphologists.