ABSTRACT
In many large open pit mines, relatively small changes in slope angle usually result in corresponding changes in project value that are measured in tens of millions of dollars. Most mining companies select slope angles on the basis of a relatively arbitrary factor of safety. However, this approach does not provide a quantitative assessment of what the failure risk of the slope is and, therefore, does not permit the evaluation of the penalty of failure on one hand, or conservative design on the other. Consequently, the decision to base a slope design on a particular factor of safety is most unlikely to yield the optimum economic slope design.
