Some mountain tunnels suffer from deformation and cracks caused by earth pressure, and such damage can progress with the passage of time for some tunnels. Due the unknown variables involved in the time-dependent deformation and destruction behavior of such tunnels, no maintenance management method has yet been established. In this study, we focused on tunnel deformation caused by earth pressure, and attempted to apply numerical analysis to the situation. As the result of the study, we achieved simulation of the behavior of tunnel deformation as time progressed and demonstrated the applicability of determination for appropriate timing and countermeasure types.