Gray, I 2020, 'Rock property determination', in J Wesseloo (ed.), UMT 2020: Proceedings of the Second International Conference on Underground Mining Technology
, Australian Centre for Geomechanics, Perth, pp. 379-400, https://doi.org/10.36487/ACG_repo/2035_20
Mining projects vary greatly in their location and rock properties. Despite this, the testing processes used to determine how they will behave geotechnically have become remarkably similar and more of a rote process. Test methods should be carefully tailored to suit all the possible behaviours of the rock mass. In underground mining, the properties of the underground structure are inherited rather than specified, and need to be determined. Usually, parts of the underground structure are required to collapse to yield ore, while others need to resist all manner of deformation and remain safely open. This paper reviews useful testing techniques with a particular focus on measuring what is appropriate for the situation. The paper starts by presenting some new ways of looking at uniaxial testing and the use of some simple tests to measure tensile and shear strength. It reviews the measurement of anisotropy, linear and non-linear elasticity, poroelasticity, plasticity and the multiple forms of failure. These include shear failure and tensile failure. Some of the questions surrounding anisotropy are reconsidered. Finally, the paper looks at how these measurements may be used.
Keywords: rock properties, rock testing, rock stiffness, sheaFeqr strength, tensile strength
ASTM 2007, D5731-07 Standard Test Method for Determination of the Point Load Strength Index of Rock and Application to Rock Strength Classification, ASTM International, West Conshohocken.
ASTM 2020, D2936-20 Standard Test Method of Direct Tensile Strength of Intact Rock Core Specimens, ASTM International, West Conshohocken.
ГOCT (Gost) 1988, 21153.5-88 Method for the determination of rock shear strength under compression, USSR State Publisher.
Gray, I, Zhao, X & Liu, L 2018, ‘The Determination of Anisotropic and Nonlinear Properties of Rock through Triaxial and Hydrostatic Testing’, Proceedings of the 10th Asian Rock Mechanics Symposium, International Society for Rock Mechanics and Rock Engineering, Lisbon.
Hoek, E & Franklin, JA 1968, ‘A simple triaxial cell for field and laboratory testing of rock’, Transactions of the Institution of Mining and Metallurgy, vol. 77, pp. A22–A26.
Huber, M 1923, ‘The theory of crosswise reinforced ferroconcrete slabs and its application to various important constructional problems involving concrete slabs’, Der Bauingenieur 4, vol. 12, pp. 354–360.
Ulusay, R & Hudson, HA 2007, The Complete ISRM Suggested Methods For Rock Characterization, Testing And Monitoring: 1974-2006, ISRM Turkish National Group, Ankara.