Fourie, AB & Haines, A 2007, 'Obtaining Appropriate Design Parameters for Slopes in Weathered Saprolites', in Y Potvin (ed.), Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 105-116.
In many open pit operations, the near-surface profile exposes weathered material. If this weathered material
is shallow, or still relatively competent, it presents no major problems and conventional design approaches
remain relevant. However, in some cases the weathered profile may be very deep such that the material
cannot be considered as rock. A common approach in these circumstances is to use designs based on soil
mechanics principles. However, some recent failures of slopes in highly weathered, saprolitic profiles have
highlighted inadequacies in this approach. A case study is presented from a mine in Guinea, West Africa,
where the approach was to obtain very high quality block samples from the saprolitic zone for testing in the
laboratory to obtain truly undisturbed material properties and ultimately provide much improved design
parameters. The pit has now been in operation for over six years and the performance of the excavated
slopes in the saprolitic material validated the approach adopted.
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Obtaining Appropriate Design Parameters for Slopes in Weathered Saprolites A.B. Fourie, A. Haines
116 Slope Stability 2007, Perth, Australia