Correlations between various rock mass classifications systems, including Laubsher (MRMR), Bieniawski (RMR), Barton (Q) and Hoek and Marinos (GSI) Systems

Author(s): 
Andrea Russo, Esteban Hormazabal
Date: 
Wednesday, November 20, 2019
First presented: 
XVI Panamerican Conference on Soil Mechanics and Geotechnical Engineering
Type: 
Published paper
Category: 
Rock Mechanics
Empirical rock mass classification systems are widely used in the practice of mining engineering, especially in the early stages of engineering design of mining infrastructure. This stage involves preliminary assessment of ground support needs for drifts and shafts, stability analysis of pillars and stopes, stability analysis of slopes in open pit mines, and others. During this preliminary stage of the design, mining engineers are required to consider different mining methods and mine designs, as well as underground and open pit alternatives. Crucial to design is the proper characterization of the rock mass, during and after the field data collection phase, in terms of available rock mass classification systems, such as Laubscher (MRMR), Bieniawski (RMR), Barton (Q) and Hoek & Marinos (GSI) systems.
Because the rock mass characterization is normally done in terms of one (or rarely more than one) of these systems, and because different mechanical assessment tools used in this and later stages of mining design typically are expressed in any of the systems, it is important to be able to properly correlate rock mass classification ratings in the different rock mass classification systems. This process of correlating the ratings is not straightforward and has not been extensively treated in the literature. The aim of this paper is to address the problem of correlating rock mass classification information, and to propose new relationships for correlation of ratings, in particular, equations that allow to correlate the Laubscher and the Bieniawski systems, and the Barton and the Hoek Marinos systems.

Feature Author

Andrea Russo

Mr. Russo has 25 years of experience in the mining industry. He has worked in porphyry copper deposits such as El Teniente and Chuquicamata underground project acquiring a strong experience in geological, structural and geotechnical mapping for underground mining, geological and geotechnical logging of drill holes and identification and characterization of geotechnical domains and lithologic model update. He has a strong experience in geotechnical characterization of rock mass according to Laubscher, Barton, Bieniawsky and GSI of Marinos & Hoek classification systems, geomechanical laboratory tests analysis, definition of the caving sequence and caving orientation. Definition of ground support through empirical methods such as Barton´s Q and validation through numerical models such as Phase2. He has worked on various open pit projects analyzing slope stability. He has worked on an environmental project acquiring experience in rock mass grouting using the GIN method. For his degree thesis he worked on the genetic model of several ore bodies in SW Sardinia (Italy) (SEDEX type deposits). His doctoral work involved the tectonic - sedimentary evolution of a carbonate platform of the Lower and Middle Cambrian in the NW of Spain and the genetic model of two mineralized levels at the base and top of the formation (SEDEX type deposits).

Principal Geologist (Rock Mechanics)
PhD in Natural Resources
SRK Santiago
Esteban Hormazabal
Esteban is a Civil Mining Engineer and holds a Master of Science (Geophysics) specialized in applied hydrogeology. He has 24 years of specific experience in geotechnical engineering, rock mechanics and geotechnical instrumentation, having worked in different mining and civil engineering projects. 
 
Additionally, he is an expert in analysis and geomechanical design of underground mining and surface excavations using 2D and 3D numerical modelling, stability analysis and slope design in open pits and waste dumps. 
 
He has led different and important open pit and underground mining projects in Argentina, Brazil, Chile, Colombia, Kazakhstan, Mexico, Peru, Russia, Uruguay and USA. 
 
Esteban has authored several publications and has been speaker at different national and international conferences. He is a Competent Person of AusIMM and the Commission for the Qualification of Competencies in Mineral Resources & Reserves of Chile (QP). He has been professor of  the Rock Mechanics Chair at the Universidad Católica de Chile from 2013-2018.

 

Head of Rock Mechanics Services
Min Eng, MSc (Geophysics), MAusIMM, SAIMM, CRIRSCO
SRK Santiago
SRK Worldwide