Analytical solution of circular openings subjected to seepage in Hoek-Brown media

Taking into account of seepage force, the elastoplastic solution of circular openings is derived by using Hoek-Brown failure criterion. The ground reaction curve, relation curve between radius of plastic zone and supporting force of tunnel wall and relation curve between radius of plastic zone and gravity stress of rock mass based on Hoek-Brown failure criterion are drawn, with seepage being considered. By comparing with the curves based on Mohr-Coulomb yield criterion and the curves without considering seepage, we concluded that: the radial displacement of tunnel wall and radius of plastic zone by Hoek-Brown failure criterion are larger than the results by Mohr-Coulomb yield criterion. For good quality rock masses, the radius of plastic zone based on Hoek-Brown failure criterion is much larger than the results by Mohr-Coulomb criterion. The effect of seepage effect on the radius of plastic zone and radial displacement of tunnel wall for underground opening is significant.