The mechanical behavior of a shotcrete lining is analyzed in this paper using the convergenceconfinement approach. A calculation procedure is presented which is able to provide the  reaction curve of a lining with increasing stiffness, by taking into account the variability due  to time of the shotcrete stiffness and strength, as well as the time-table during tunnel  excavation. The proposed procedure is a very useful tool for understanding the behavior of  this widely used support and providing the change of the safety factor of the lining in  excavation process. From examples calculation, influence of the parameters on the reaction  curve and safety factor such as excavation footage, the cycle time, the time constants of  shotcrete and tunnel radius are discussed.