Abstract
Many authors have been proposed several correlation equations between geomechanical classifications and strength parameters. However, these correlation equations have been based in rock masses with different characteristics when compared to Brazilian rock masses. This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses. Four classification systems have been used; the Rock Mass Rating (RMR), the Rock Mass Quality (Q), the Geological Strength Index (GSI) and the Rock Mass Index (RMi). A strong rock mass and two soft rock masses with different degrees of weathering located in the cities of Ouro Preto and Mariana, Brazil; were selected for the study. Correlation equations were used to estimate the strength properties of these rock masses. However, such correlations do not always provide compatible results with the rock mass behavior. For the calibration of the strength values obtained through the use of classification systems, stability analyses of failures in these rock masses have been done. After calibration of these parameters, the applicability of the various correlation equations found in the literature have been discussed. According to the results presented in this paper, some of these equations are not suitable for the studied rock masses.
Highlights
Rock masses are made of intact rocks and discontinuities
This paper aims to study the applicability of the geomechanical classifications to obtain strength parameters of three Brazilian rock masses
The point load test proved to be applicable in TLD-01 and TLD-02 slopes and provided uniaxial compressive strength values within the range obtained through the geological hammer test
Summary
In order to quantify the quality of rock masses, several authors have proposed geomechanical classifications systems, like the RMR (Bieniawski 1989), the Q system (Barton et al 1974), the GSI (Hoek 1994) and the RMi (Palmström 1995). Stability analysis is a good tool for estimating mechanical properties of rock masses. Stability analysis methods have been thoroughly researched They present reliable results and generally represent what really occurs in rock masses. The knowledge of strength properties by in situ tests is highly relevant, but difficulties associated with sampling and execution of them precludes their use, leading to the employment of indirect methods, like the geomechanical classifications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
