Modification of rock failure criteria considering the RMR caused by joints

The aim of this study is to present a modification of the failure criteria of rock masses, separately considering the effect that the Bieniawski’s rock mass rating (RMR) has due to joints, as well as the RMR linked to compressive strength of the mass rock. This modification can be applied to three of the already existing criteria: that of Bieniawski–Yudhbir–Kalamaras, that of Sheorey, and that of Hoek–Brown, comparatively analysing the effects of the three modifications that have been proposed. The new, modified criterion will be validated with new data obtained in a marble mine exploited by means of rooms and pillars. The values observed and measured in the mine are compared to those obtained through numerical modelling of the pillars, using the Análisis Lagrangiano de Medios Continuos, Lagrangian Analysis of Continuous Media (ALMEC) program. Finally, several conclusions related to the application of these rock failure criteria to the analysis of mining excavation of rooms and pillars will be proposed.