Use of the block punch test to predict the compressive and tensile strengths of rocks

This study aimed to explore the applicability of the block punch test in estimating uniaxial compressive and Brazilian tensile strengths of granite, schist and sandstone from India. It was experimentally shown that when predicting uniaxial compressive strength of rocks, the block punch test is as useful as the point load test. Efficacy of the existing empirical equations for predicting uniaxial compressive strength by the block punch index was also evaluated. Prediction of Brazilian tensile strength by block punch index appears to be more precise than by the point load strength. Performances of the existing strength anisotropy transformation factors in the literature in order to normalize the block punch index in the direction perpendicular to foliations were assessed based on the results of the tests performed on the schistose rocks. (C) 2012 Elsevier Ltd. All rights reserved.