A 2023 perspective on Rock Mass Classification Systems

Dozens of rock mass classification systems (RMCS) have been developed since the 1950s for applications like tunnelling, mining or rock slopes. The abundance of systems and ongoing discussions amongst scholars and practitioners are symptomatic of the complexity of the problem and show that the community has not converged to commonly accepted procedures. Based on an online survey, this study aims to give an overview of the international spread of RMCS in use. The survey shows that GSI, RMR and the Q-system are the dominating systems in the world for underground engineering- and slope-related applications and thus have managed to prove their practical applicability throughout up to five decades. Conversely, the survey highlights that almost no system developed in the past 25 years has become internationally accepted, thus raising the question of whether today's RMCS can still live up to technological and scientific standards in 2023?