Stability of slopes characterised by colluvium: Investigation, analysis and stabilisation

© 2018 ISRM International Symposium 2000, IS 2000. All rights reserved. The stability of slopes characterised by colluvium presents major challenges to developers, engineers and government authorities. The risk of slope failures is higher in areas characterised by high altitudes and high intensity and prolonged rainfalls. Unfortunately, the routine methods of geotechnical investigation and analysis normally adopted for steeply sloping sites may not be applicable, largely due to the composition and characteristics of colluvium. Practical experience and innovative engineering is therefore required. This paper presents a discussion on the available site investigation techniques for assessing colluvium slopes. The usefulness of in situ and laboratory tests is reviewed, together with the applicability of the derived soil parameters for the engineering analysis. The effects of rainfalls on the stability of a slope and precautionary measures for ensuring adequate long-term stability are discussed.