Non-linear dynamic support optimization method for non-uniform pressure circular tunnel considering the effect of damage

摘要

Based on non-linear Hoek-Brown criterion, a new approximate solution of deformation and plastic zone radius of circular tunnel is deduced under non-uniform pressure. In the plastic region, three different, Young's modulus attenuation models are applied to solve the plastic zone deformation. The results show that the lateral pressure coefficient (LPC), dilatancy coefficient, buried depth and Young's modulus attenuation exert important effects on the surrounding rock state. Under the influence of LPC, the radius and displacement of plastic zone show non-uniform variation; then, the maximum value of the ground response curve is gradually shifted from the side to the roof. With the burial depth and dilatancy coefficient increase, the surface displacement presents the non-linear increase characteristic. Besides, the influence of Young's modulus on the plastic zone deformation is not only related to its attenuation model, but also closely related to the surface location and LPC of surrounding rock. Based on the above research, a non-linear dynamic support optimization method for non-uniform pressure circular tunnel is proposed.