A CONSIDERATION ON THE EFFECT OF VOID BEHIND THE LINING BASED ON THREE DIMENSIONAL ELASTOSTATICS

Abstract

 To consider the effect of the void on the tunnel lining, three-dimensional behavior of a cylindrical tunnel with a void behind the lining under isotropic compression and sher loading are theoretically analyzed. Numerical results show that the presence of a void causes a negative effect to the lining associated with the change of the stress state of the lining from the axial thrust to bending moment. The tensile stress caused by the void can occur in the inner lining when the void length in the longitudinal tunnel direction is longer than the tunnel radius. Effect of the void on the lining increase proportional to the void length in the longitudinal tunnel direction, and the upper limit of the length strongly depend on the void length in the circumferential direction.