Use of Mohr’s Circles for Connection and Model Estimation of Strength Data of Different-Size Rock Samples

An approach is proposed to connecting strength data of different-size rock samples by the linear shear-to-normal stress dependence. The data are presented by Mohr’s circles. The key moment is the determination of centroids for uniaxial compression and tensions areas enveloped by Mohr’s semi-circles. Using coordinates of the centroids, the shear stress–normal stress curves are plotted. Thereupon, the model estimate of missing data (ultimate compression and tension strengths) is constructed for rock samples. The missing ultimate strengths are estimated in terms of meta-siltstone.