Abstract

This work aims to emphasise the importance of geoengineering software use on the study of rock-mass classifications for rock engineering design and ground behaviour. This approach demonstrated the importance of geomechanical classifications (e.g., Rock Mass Rating – RMR, Rock Tunnelling Quality Index – Q-system, Surface Rock Classification – SRC, Rock Structure Rating – RSR) and rock engineering or hydrogeomechanical indexes (e.g., Rock Quality Designation – RQD, Geological Strength Index – GSI, Hydro-Potential Value – HP, Rock Mass Index – RMi), as well as geotechnical database and analysis systems (e.g., Basic Geotechnical Description of Rock Masses – BGD, Tunnel Information and Analysis System – TIA). For this purpose a geomechanical calculator – MGC–RocDesign|CALC: Mining Geomechanics Classification System Calculator for Rock Engineering Design – was created and developed to make it simple, fast and to accurate the study of rock-mass classifications for tunnelling and geomechanical zoning map purposes. Finally, the general anatomy and some remarks about the applicability, capabilities and limitations of the geomechanical calculator MGC–RocDesign|CALC are presented.

Introduction

Barton et al. (1977) stated this important issue: "No matter how many sophisticated rock mechanics test programs and finite element analyses are performed, design engineers will come back to the basic question: is this bolt spacing, shotcrete thickness, or unsupported span width reasonable in the given rock mass?". This outstanding quotation is the basis for the key role that rock discontinuous behaviour provides rich experiences for those who value reality, even when reality has to be simplified by some empiricism (Barton 2012). However, some technical procedures must be fulfilled to avoid systematic or random errors (e.g.,Terzaghi 1965, ISRM 1981, Priest 1993, CFCFF 1996) and the intrinsic geological variability and uncertainty (e.g., Hudson 1992, Bieniawski 1997, Mazzoccola et al. 1997, Keaton 2013, Chaminé et al. 2013, 2014).

Rock mass classification schemes and geotechnical indexes for tunnel design have been developed for over 130 years.

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