Influence of scale on the uniaxial compressive strength of brittle rock

The prediction of failure conditions has always been a critical issue in rock engineering. One of the factors that makes this a complex problem is the influence of scale (size) on the response of rocks and rock masses. A variety of approaches have been developed and used to estimate the strength of rock media at different scales. These include a scaling function proposed by the authors, which is partly based on the statistical variability of uniaxial compressive strength of intact rock samples. In this paper, this approach is revisited. A simple method is presented for determining the required parameters for predictive applications, using standard laboratory test results. The validity of the proposed approach is evaluated using test results recently obtained by the authors and with some data taken from the literature.