Based on the unified strength theory and a non-associated linear flow rule

an elastoplastic unified solution for displacements around a deep circular tunnel is presented

which takes the true elastic strains in the plastic zone into account. The effects of intermediate principal stress and dilatancy are considered in the unified displacement solution; so the unified solution obtained has very broadly theoretical value. Compared with the simplified analytical solutions for displacement in the literature show that the influence of the elastic strains in the plastic zone on tunnel displacements is significant. The results of the simplified analytical solutions are less than those of the unified solution. The differences between the simplified analytical solutions and the unified solution are strongly related to the effects of intermediate principal stress and dilatancy. The strength potentials of rock mass are achieved due to considering the intermediate principal stress effect. The effect of dilatancy is important for the tunnel support design.