I am studying fully dynamic analysis with plaxis 2D. I've created a tunnel shape which is circular. and I am analysing the tunnel with different depth. Firts picture shows 14 meter of overburden depth dynamic time-moment graph. Seconda graph represent the 42 meter of overburden depth dynamic time-moment graph. I thinkis first graph seems to be okey. I mean when the earthquake loading is done I expect the moment to decrease some way. But in the second graph my expactation doesn't occur. The models are completely same, I just changed the tunnel depth. İs this something about model conditons, boundary ? I just cant find it.