Title: Prediction of rock fracture toughness modes I and II utilising brittleness indexes

Authors: O. Saeidi; S.R. Torabi; M. Ataei; S.H. Hoseinie

Addresses: Faculty of Mining Engineering, Petroleum and Geophysics, Shahrood University of Technology, University Ave., Hafte-Tir Square, Shahrood 3619995161, Iran ' Faculty of Mining Engineering, Petroleum and Geophysics, Shahrood University of Technology, University Ave., Hafte-Tir Square, Shahrood 3619995161, Iran ' Faculty of Mining Engineering, Petroleum and Geophysics, Shahrood University of Technology, University Ave., Hafte-Tir Square, Shahrood 3619995161, Iran ' Department of Mining Engineering, Hamedan University of Technology, Hamedan 3619995161, Iran

Abstract: Fracture toughness and brittleness are of the most crucial rock features for underground excavation and drilling in rock mass. Developed standard tests to determine rock fracture toughness are very difficult as well as time consuming; furthermore, they require high-level accuracy during sample preparation and testing. An attempt has been made to propose simple relations to determine fracture toughness modes I and II based on brittleness indexes B1, B2 and B3 in this paper. The data for regression were gathered from the literature, including modes I and II fracture toughness, uniaxial compressive strength and tensile strength. It was obtained that both fracture toughness modes I and II of different rock types give reasonable correlations with brittleness index B1. No correlation was observed between fracture toughness modes and other brittleness indexes.

Keywords: rock fracture toughness; mode I; mode II; brittleness indexes; uniaxial compressive strength; tensile strength; rock features; underground excavation; drilling.

DOI: 10.1504/IJMME.2012.052442

International Journal of Mining and Mineral Engineering, 2012 Vol.4 No.2, pp.163 - 173

Received: 08 Oct 2012
Accepted: 20 Dec 2012

Published online: 24 Mar 2013 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article