Next Article in Journal
Process Design Aspects for Scandium-Selective Leaching of Bauxite Residue with Sulfuric Acid
Previous Article in Journal
Rare Earth Element Phases in Bauxite Residue
Previous Article in Special Issue
Role of Volcano-Sedimentary Basins in the Formation of Greenstone-Granitoid Belts in the West African Craton: A Numerical Model
Article Menu
Issue 3 (March) cover image

Export Article

Open AccessArticle
Minerals 2018, 8(3), 78; https://doi.org/10.3390/min8030078

Estimating RMR Values for Underground Excavations in a Rock Mass

1
Geoárea, Environmental and Geotechnical Consultants, 2610-276 Alfragide, Portugal
2
GeoBioTec & Earth Sciences Department, FCT, NOVA University of Lisbon, 2829-516 Caparica, Portugal
*
Author to whom correspondence should be addressed.
Received: 30 January 2018 / Revised: 13 February 2018 / Accepted: 21 February 2018 / Published: 25 February 2018
(This article belongs to the Special Issue Geological Modelling)
Full-Text   |   PDF [12057 KB, uploaded 25 February 2018]   |  

Abstract

During underground excavations for civil or mining engineering purposes, the variations in rock mass quality are important, especially for the design of the most suitable support to be applied to ensure stability. The aim of this investigation is to model the expected behavior of the ground, and thus to predict the scenarios indicating potential variations in the quality of the rock mass during underground excavation. When considering the rock mass rating (RMR) values observed at the excavation face in six study cases, which together total more than 27 km in length of underground excavation by drilling and blasting (D&B), and based on the observed RMR values at the face, the most probable value (1–100) is estimate for the RMR index at the five subsequent front advances. It is concluded that, up to about 20 m ahead of the current face, the quality of the rock mass for the next advances is close to the quality observed at the present face, and that, with increasing distance, there is a greater deviation of RMR values with respect to the quality observed at the current face. View Full-Text
Keywords: underground excavation; RMR values modeling; estimation; rock mass; geotechnical uncertainty; kriging underground excavation; RMR values modeling; estimation; rock mass; geotechnical uncertainty; kriging
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Santos, V.; da Silva, P.F.; Brito, M.G. Estimating RMR Values for Underground Excavations in a Rock Mass. Minerals 2018, 8, 78.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Minerals EISSN 2075-163X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top