Gao, X 2020, 'The effect of anisotropy orientation on the sedimentary rock strength estimated
by point load testing strength, Pilbara, Australia', in PM Dight (ed.), Proceedings of the 2020 International Symposium on Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 657-666, https://doi.org/10.36487/ACG_repo/2025_41
Mine slope geotechnical design requires an engineering estimation of the intact rock’s uniaxial compressive strength, which is influenced by the anisotropic nature of sedimentary rocks. In order to determine the rock’s anisotropic behaviour, numerous rock samples from diamond drilling were tested in the field by using the point load test (PLT) method. The effect of anisotropy on the calculated point load strength ( from axial and diametral point load testing was investigated. The finding of this paper can be used to select σci input for the Hoek–Brown failure criteria based on low-cost PLT results.
Keywords: anisotropy index, point load test, point load strength, banded iron formation, shale
ASTM International 2009, Standard Test Method for Determination of the Point Load Index of Rock (ASTM D5731-05), ASTM International, West Conshohocken.
Bieniawski, ZT 1975, ‘Point load test in geotechnical practice’, Engineering Geology, vol. 9, no.1, pp. 1–11.
Broch, E & Franklin, JA 1972, ‘Point load strength test’, International Journal of Rock Mechanics and Mining Sciences, vol. 9, no. 6, pp. 669–697.
D’Andrea, D.V, Fisher, RL & Fogelson, DE 1964, ‘Prediction of compression strength from other rock properties’, Colorado School of Mines Quarterly, vol. 59, no. 4B, pp. 623–640.
Galvan, M, Preciado, J & Seron, J 2014, Correlation between the point Load Index Is(50), and the Resistance to Unconfined Compression in Limestone from The Comunidad Valenciana, Spain, ACTA Geotechnica Slovenica, University of Maribor, Maribor, viewed 15 December 2019,
Mercer, K 2012, The history and development of the anisotropic linear model: part 1, July 2012 newsletter, Australian Centre of Geomechanics, Perth, viewed 22 September 2019,
Rio Tinto 2010, Geology and mineralogy of the Hamersley Province ores, unpublished.
Standards Australia Limited 2007, Method 4.1: Rock strength tests-Determination of point load strength index (AS 4133.4.1-2007), Standards Australia Limited, Sydney.
Standards Australia Limited 2013, Method 4.3.2: Rock strength tests-Determination of the deformability of rock material in uniaxial compression-Rock strength less than 50 MPa (AS 4126.96.36.199-2013), Standards Australia Limited, Sydney.