Parameter equivalent for Mohr-Coulomb and Hoek-Brown criteria in the case of rock tunneling

摘要

The determination of an equivalent Mohr-Coulomb (M-C) envelope to the empirical HoekBrown (H-B) criterion has become an important problem in geotechnical and mining engineering. Some researchers have proposed different methods for it. However, there are a certain deviations by applying these methods to deep tunnels. In this paper a simple method by a new best fitting for the minor principal stress on from the support pressure to the critical pressure is presented. The presented method is based upon equating the areas covered not only by the envelopes but also by the derivative envelopes of the two criteria. Some examples analyzed for both given and undetermined support pressures show that this method is relatively simple and exhibits comparatively approximate results to the prototype H-B for constructing the Ground Response Curves (GRC) in deep tunnels.