Validation of Hoek–Brown failure criterion charts for rock slopes

Although stability charts suggested by Hoek and Bray on the basis of Mohr–Coulomb criterion are used for rock slopes, but complete and precise recognition is required for distinguishing cohesive strength and Mohr–Coulomb equivalent internal friction angle for rock mass. The paper by Lia et al. [6] is the only one that introduced rock slope charts according to Hoek–Brown failure criterion. In this paper, at first, this type of charts is introduced. Then, Mohr–Coulomb failure criterion charts [2] are compared and validated with Hoek–Brown failure criterion ones [6]. Next, Bishop method utilizing Slide software is compared with Hoek–Brown failure criterion stability charts. Average standard deviation (ASD), root mean square error (RMSE) and variance account for (VAF) were used for the comparison. According to the results, because of high distribution and very low correlation among the comparisons, Hoek–Brown failure criterion charts are not efficient.