Journal of the Southern African Institute of Mining and Metallurgy
On-line version ISSN 2411-9717
JOUGHIN, W.C.; JAGER, A.; NEZOMBA, E. and RWODZI, L.. A risk evaluation model for support design in Bushveld Complex underground mines: part II-Model validation and case studies. J. S. Afr. Inst. Min. Metall. [online]. 2012, vol.112, n.2, pp. 95-104. ISSN 2411-9717.
A risk evaluation model has been developed that enables the quantification of expected injuries and economic losses resulting from rockfalls associated with a support system in a given geotechnical environment, which is described in Part I (Joughin et al., 2011b). Part II presents the validation of the risk evaluation model. Underground mapping of joints and rockfalls was carried out to provide data for field calibration of the model. This survey was limited to small rockfalls,due to the relatively short period of mapping. Therefore the model was also correlated with rockfall and rockfall injury data collected by mine personnel. The analyses showed that the model provides a reasonable estimate of the expected frequency and size of rockfalls and the frequency of rockfall injuries, but further work is required to enhance the model. Three case studies are presented, which show the benefits of improved support systems from both economic and safety perspectives. This work has demonstrated that the risk evaluation model and the software developed are immediately useful, but further work is required to develop and improve the tools.
Keywords : risk evaluation; risk based design; probabilistic design; statistical keyblock analysis; support design; joint mapping.