Description :
Abstract
A knowledge of angle of repose and stability of waste rock dump slopes is of vital importance at all mine sites. Conventional slope stability analyses model slopes in plane strain. In reality, slopes advance in a curvilinear pattern in plan and hence produce slope faces that are either convex or concave in plan. The three—dimensional shape of the waste rock dump is similar to that of a solid body of revolution, which may be modelled using a two-dimensional grid and a radial coordinate system. A 250 m high in-pit waste rock dump at Kidston Gold Mines Limited, North Queensland, Australia was modelled using this technique. The analysis showed that adopting a non-linear Mohr-Columb envelope resulted in a more deeply—seated failure plane than would occur using a linear envelope. A slope with a concave advancing face in plan was stable at an angle at least 2° steeper than an identical slope advancing in a straight line in plan. On the other hand, a convex advancing slope was only just stable at an angle of 0.5° flatter than an identical slope advancing in a straight line.