Correlation between uniaxial compression strength and point load index for Irish Caledonian granites
McCabe, Bryan A. Flynn, Kevin N. Baxter, Sadhbh
McCabe, Bryan A.
Flynn, Kevin N.
Baxter, Sadhbh
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Publication Date
2022-08-25
Type
conference paper
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Citation
McCabe, Bryan A., Flynn, Kevin N., & Baxter, Sadhbh. (2022). Correlation between uniaxial compression strength and point load index for Irish Caledonian granites. Paper presented at the CERI 2022, Dublin, Ireland, 25-26 August. http://www.cerai.net/
Abstract
While the Uniaxial Compression Strength (UCS) test is the gold standard for determining the UCS of rock for geotechnical and mining applications, empirical correlations between UCS and other test measurements are useful in situations where intact cores are difficult to retrieve and/or the scope of UCS testing is constrained by budget. UCS is most commonly correlated with the cheaper and more accessible Point Load Index (PLI) measurement. In ASTM D5731-16 (2016), it is recommended that site-specific correlations are developed between UCS and Is(50), the point load index adjusted to a specimen diameter of 50 mm, as a means of estimating UCS indirectly. However, in the absence of site-specific data, a UCS/Is(50) ratio in the range 18 to 24.5 (dependent on core diameter) may be used. In this paper, the relationship between UCS and Is(50) is explored for Caledonian granites from three regions in Ireland. The effects of variables such as the direction of point load application (diametral versus axial), UCS core diameter and aspect ratio and Rock Quality Designation are also considered. These data supplement the very limited information on UCS-PLI relationships published for granite internationally, while complementing a similar study recently conducted for Calp Limestone in the greater Dublin area.
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Publisher
Civil Engineering Reesearch Association of Ireland
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Attribution-NonCommercial-NoDerivatives 4.0 International