跨断层隧道抗减震措施性能振动台试验研究

跨断层的隧道工程在中国高烈度地震区已经越来越普遍。针对目前土木工程抗震设计规范对跨断层隧道的不适用性,通过振动台模型试验研究了隧道结构常规与新型抗减震措施在地震动力荷载作用下的响应特性和破坏机理。结果表明：断层滑动装置在单体模型箱中模拟断层滑动状况良好;套管式可变形结构的抗减震性能最好;减震层可以提高隧道结构整体的耐震性能;减震缝通过提高隧道结构纵向自由度而减轻震害。分析了隧道结构在地震中发生破坏的初始位置与破坏过程,揭示了各种抗减震措施的作用机理。最后,将地震烈度与隧道结构破坏过程相结合,提出了各种抗减震措施的适用条件。为研发新型隧道抗减震措施与隧道抗震设防提供参考。

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.