OPEN-PIT OPTIMIZATION .2. PRODUCTION SCHEDULING AND INCLUSION OF ROADWAYS

Two aspects of open-pit optimization that are often neglected are prod uction scheduling and the incorporation of haul roads and safety berms in the design. The production scheduling problem is part of the wider and, as yet, unsolved problem of optimal open-pit design with the use of maximum net present value as the optimizing criterion. The approac h that is taken here is to use dynamic programming to schedule the blo cks that are contained in a previously optimized open-pit design. The standard approach to the incorporation of haul roads and safety berms in open-pit designs is simply to work with average slopes that are les s steep than the ultimate pit slopes. These average slopes are determi ned by the widths and slopes of haul roads. A simple block constructio n is described that allows haul roads to be incorporated automatically and in a near optimal manner on the basis of a number of optimizing c riteria.