A Comparative Analysis Of Rock Mass Classification Schemes In Part Of The Fimiston Open Pit Operation In Kalgoorlie, Western Australia

Data necessary for rock classification have been collected in part of the Fimiston Open Pit in Kalgoorlie using both scanline mapping and diamond hole logging. These data have used to compare and contrast the three main rock mass classification schemes (RMR, Q and GSI) and, in particular, assess correlations between them based on previously published empirically derived relationships. The equation proposed by Moreno (1980) was found to provide the most accurate correlation between RMR and Q’. Although the correlation coefficient provided by this method was relatively low for the study data, the average difference between the converted Q’ and RMR was approximately 2.5% and did not exceed 6% for any of the boreholes or scanlines. Given the relatively inaccurate and subjective nature of the classification systems, the correlation is considered suitable for use in slope engineering applications. The input parameters for RMR and Q and not equivalent, and providing more equivalent indices may theoretically allow a more accurate correlation to be developed. However, the correlation proposed by Goel and others (1996) does not provide a more accurate relationship for the two main structural domains in this study when compared to the correlation proposed by Moreno (1980).