Estimating the rock strength from a crushability index

Abstract

Uniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) are widely used in rock engineering. However, preparing standard samples for the strength tests may not always be possible for weak rocks. On the other hand, only rock fragments are available to estimate the rock strength in some cases such as drilling. Therefore, developing some models for estimating the rock strength from rock fragments will be useful. In this study, a crushability index (CI) was described from crushing test and the possibility of predicting UCS and BTS from this index was investigated. Strong and significant linear correlations were found between the CI and both the UCS and BTS. It is concluded that the UCS and BTS of rock can be estimated from the CI. The suggested method is especially useful for the drilling industry and for the cases where there are not enough samples for the standard tests. © 2016 Taylor & Francis Group, London.