Abstract: The formula of elastoplastic matrix for the generalized Hoek-Brown failure criterion used in the finite element analysis, has been deduced. And then, the criterion is used for simulating the construction stages of a cutting rock slope in the elastoplastic finite element analysis. Meanwhile, the strength reduction analysis is also executed by using the equivalent Mohr-Coulomb parameters in order to find out the evolvement of critical failure model during the construction. It is shown that the development rules of the stress and strain, the displacement, the stability and the critical slip during the excavating are coincident with the results gained by using the traditional Mohr-Coulomb failure criterion. However, the results also show that using the equivalent Mohr-Coulomb parameters gained by the Hoek’s formula (2002), may overestimate the stability of slope.

Key words: stability, generalized Hoek-Brown failure criterion, strength reduction technique