The Qualitative Stability Graph for Open Stope Design – Recent Developments

ABSTRACT: The Stability Graph is an accepted tool for open stope design in the metalliferous underground mining community. Since its development in 1981, it has undergone several modifications and remains active research subject to date. Admittedly, while some of the suggested changes have been called into question for their practical relevance, others have gone a long way to improve the reliability of the method in minimizing dilution in open stope mining. One of the major concerns that have emerged in researching some suggested modifications to the design tool appears to be those authors behind such propositions neither understand how the method works nor the database used to develop the method. Such authors rely on the application of statistics to the database with no idea of the practical implications of the outcome of their analysis except that it is probably statistically beautiful in theory. The downside of this playing with numbers is that so much confusion has been created in the mining industry as to what is useful in using the method for open stope design. This paper cautions against the misuse of statistics in geoengineering with emphasis on the Stability Graph and provides recent developments relevant to improving the reliability of the method in reducing dilution in open stopes. Furthermore, the long outstanding question of whether the original Stability Graph number factors or the modified Stability Graph number factors should be used or not is answered.