The correlation between RMR and Q systems in parts of Iran

One of the approaches for characterising rock masses with discontinuities due to the presence of engineered designs is to use rock mass classification. Thus far, many classification systems, including RMR, Q, and GSI, have been proposed in the literature. Their parameters are based on site investigations, such as surface/subsurface fracture studies and well coring, as well as laboratory experiments. When sufficient information is not available, the utilisation of several rock mass classification systems is useful to compile a more complete understanding of the composition and characteristics of a rock mass. Thus, many correlations have been drawn to relate different systems, especially between RMR and Q systems. In this study, the best correlation coefficient between RMR and Q systems was determined with the aim of suggesting a new potential correlation for various geotechnical activities in parts of Iran. To accomplish this aim, rock mass parameters for the RMR and Q systems were assessed by considering their values separately for more than 800 stations at 14 different sites and applying statistical procedures to the data. Finally, a new correlation was determined.