Using index tests to predict the compressive strength of crystalline rocks

Abstract

Due to its ease of use and other advantages, the point load test has been reported in the literature as an indirect means of measuring the uniaxial compressive strength (UCS) of rocks. Crystalline rocks, including quartzite, gneiss, granites and charnockite from the Precambrian basement complex of Ado-Ekiti, Nigeria were evaluated to assess the relationship between the UCS and point load strength. A regression analysis was carried out for all the rock types and for different types separately. Strong linear relationships were obtained in all cases, although the coefficient of correlation increased when the rock types were considered separately. This study has shown that the effect of different rock lithology must be taken into consideration when deriving the relationship between these two parameters.