Linear Mohr–Coulomb strength parameters from the non-linear Hoek–Brown rock masses

Abstract

Most conventional computer codes, design practice and standards in rock engineering are formulated in terms of a linear Mohr–Coulomb (MC) failure criterion. However, experimental data shows that the failure of almost all types of rock masses follows a modified Hoek–Brown (HB) failure criterion that is non-linear. In order to avoid the difficulty resulting from the non-linearity of the strength envelope of rock masses in calculation of bearing capacity, the equivalent MC strength parameters from the modified HB failure criterion are developed for practical use in engineering. From the results, it is found that the equivalent strength parameters depend on not only the non-linear HB failure criterion but also the surcharge load and self-weight, which is different from the published results.