عنوان مقاله [English]
In this paper the effect of creep is discussed. The burger body which is able to model the primary and secondary creep regions of rocks is applied. In order to analyze the behavior of circular tunnels in visco-elastic media and hydrostatical state of stresses, new relations are derived. The new proposed equations are able to predict the variations of the stresses and displacements during the time. In order to verify the analytical solution, a tunnel is analyzed numerically by using FLAC code. The results of these two analyses showed a proper agreement with the numerical analysis and an instrumented tunnel.