Stability of cemented tailings mine backfills

Ore bodies, hence mine openings and exposed backfills in large underground metalliferous mines vary in shape from relatively high and narrow to relatively low and wide. Wall rocks adjacent to the backfill may be steeply dipping or may be relatively flat-lying. Fill stability analyses must consider the details of the geometric boundaries of the fill if economical use of stabilizing cement is to be achieved. It is generally prohibitively expensive to use sufficient cement to satisfy a lower bound free standing wall design approach. This paper considers three typical fill geometries--steeply dipping and gently dipping relatively narrow fills as well as relatively wide fills--and presents the results of both analytical and physical model stability studies. It is shown that efficient use of cement can be achieved by relying on the beneficial effects of soil arching, boundary shear and reinforcing techniques.