The Consolidated Mathews Stability Graph for Open Stope Design

Abstract

The stability graph method for open stope design is one of the most widely used approaches for predicting the stability of stopes in underground metalliferous mines. The primary purpose of this work is to propose a new stability chart, which includes all relevant case histories, and to exclude parameters with uncertainties for determining stability number. The modified stability number was used to achieve this goal, and the Extended Mathews database was recalculated and compared with the new stability graph. In this study, a new refined Consolidated stability graph was developed by excluding the entry mining methods data from the Extended graph data, and only the non-entry methods data was used. The applicability of the proposed Consolidated stability chart was demonstrated by an open stope example. The probabilities of stability for each stope surface were determined using the logistic regression model and the developed Consolidated stability chart. Comparing the stability analysis results with that of other published works of the same example shows that the determined Consolidated chart, in which the entry-method data is excluded, produces a more conservative and safer design. In conclusion, the size and quality of the dataset dictate the reliability of this approach.