Shaking table tests on performances of anti-seismic and damping measures for fault-crossing tunnel structures

Fault-crossing tunnel structures are more and more universal in high intensity seismic regions of western China. The current code for aseismic design of civil engineering cannot be used for them. To deal with this problem, the seismic response characteristics and failure mechanism of routine and new anti-seismic and damping measures for tunnel structures are investigated based on shaking table tests. The results show that the self-developed sliding device can simulate fault movement successfully in a single model box. The casing-shape damping measure can provide the most effective protection, and it is the best-performing aseismic and damping measure for fault-crossing tunnels. The damping layer can enhance the general vibration strength of tunnel structures. The absorbing joint can reduce the post-seismic destruction by increasing longitudinal freedom degrees of tunnel structures. The initial destructive position and the whole destructive process of tunnels during the earthquake are analyzed. The action mechanism of various anti-seismic and damping measures are released. Finally, by analyzing the relationship between seismic intensity and destructive process of tunnel structures, the service conditions of various anti-seismic and damping measures are put forward. The above results certainly contribute to studying and developing new types of anti-seismic and damping measures for tunnels and provide references for seismic fortification of tunnels as well.