Experience in Australia with the application of the Mathews' method for open stope design

A significant open slope stability data base was developed for an Australia n mine which is similar in size to the North American data base used to dev elop he Mathews' stability graph method. Sufficient case histories were dev eloped to test he validity of using he two extant versions of he Mathews' m ethod for predicting the stability of slope wails at the case study mine. B oth gave similar predictions, despite different stability zonings and some differences in the way that the stability numbers are calculated. in genera l, the slope surfaces that were observed as unstable plotted well on both s tability graphs. However, a significant percentage of stable slopes were pr edicted to be unstable and this percentage was much greater than that for h e North American data base, indicating that he method gave more conservativ e predictions for this particular case study. The study indicated that the two versions of the Mathews' method may give r easonable first approximations To slope dimensions where local experience i s lacking or has not been documented. Nevertheless, the development of site specific zones of stability improved the predictive capability of the tech nique. Case histories documented by the authors, which included slope surfa ces with a hydraulic radius up to 55 m, were combined with the Canadian dat a base and a modified general Mathews' stability graph presented.