Abstract:Based on Newmark’s step-by-step implicit integration FEM method,the response analyses of a generic tunnel by using viscous-spring artificial boundary technique under various earthquake accelerations and multiform conditions of surrounding rocks are presented. The seismic responses of the tunnel are calculated by changing parameters of surrounding rocks within certain influencing distances to the linings. Two kinds of shock absorption measures,which are setting shock layer and grouting in the surrounding rock,are investigated. The shock absorption effects,applicability,and shock mechanisms are analyzed. The results show that the differential displacements and stresses in the lining of the tunnel decrease and the linings are protected when the two measures are used. It also shows that for weak surrounding rocks,rock grouting is an effective shock absorption measure and the aseismatic capability of surrounding rocks can be improved. For underground structures in hard rocks,the seismic effects on tunnel stability can be ignored even if tunnel is located in earthquake-prone regions,but for important projects. The results provide useful reference for the aseismatic design of tunnel.