Investigate the rock mechanics aspects of potholes in the platinum mines, their contribution to poor ground conditions, and if proactive identification is possible

Abstract

The main aim of this project was to define and quantify the effect of potholes on ground conditions in platinum stopes, and assess whether these changes could be used to predict the occurrence of potholes ahead of stope faces. In order to gain better background understanding of the effect of potholes a literature survey and interviews with platinum mining personnel were carried out. The literature survey revealed that there have been very few studies of the geotechnical aspects of potholes and almost no cohesive record of the identifiable characteristics of potholes exists. On the other hand, interviews with mining personnel indicated that there is a reasonable local understanding of the pothole phenomenon and that set rules of how to handle potholes (once they are intersected) are in place. In light of the literature survey and findings of the interviews, detailed mapping of fourteen underground sites was carried out. Analysis of this data showed that there were no easily recognizable features common to all potholes that could be used to predict the presence of potholes ahead of excavations.