Abstract: Interaction of soil and underground structure under dynamic load is a hot topic for the geological engineering.Based on the dynamic equation,using FEM and vibration mode superposition method,the response of the shield tunnel which locates in the loess area and in the dynamic activity as El Centro earthquake wave was got in the paper.The maximum acceleration and the maximum dynamic stress are at the bottom of the shield tunnel.The displacement inside of the tunnel is bigger than the outside.The m...