Joughin, W.C., SRK Consulting; Stacey, T.R., University of the Witwatersrand, South Africa
Problems with the stability and performance of rockpasses in deeplevel mines are common. This paper presents the results of an investigation into the recorded performance of rockpasses in deeplevel gold mines. Records relevant to the geological environment in which the passes are excavated, their excavation details, and their historical performance are not at all well documented on mines. In general, the quality of data available from mines is poor. The investigation showed that very large spans frequently developed in passes during use, and that rock mass quality, the orientation of the pass with respect to the dip of the strata, and the magnitude of the stress acting normal to the axis of the pass were the main factors of influence. From the historical information obtained, the risks of instability in rockpasses are identified. © The South African Institute of Mining and Metallurgy, 2005.