近断层交通隧道震害机理与结构抗减震适应性研究

With the rapid development of traffic construction in China, more and more tunnels will be inevitably built in high seismic intensity near-fault area. These tunnels always have most serious damage at earthquake, and the seismic damage mechanisms as well as the seismic response characteristics of them are also different from the tunnel built in far field of earthquake. This study based on the site characteristics of near-fault tunnel explores the research potentials by adopting comprehensive methods of theoretical analysis, numerical simulation, and model test to study the following problems which need to be settled: stick-slip effect and creep-slip effect as well as the influential factors at active fault engineering site; lining-surrounding rock interactive seismic damage mechanism of near-fault tunnel; structural earthquake resistant behavior of near-fault tunnel. The objectives of this study are to ascertain the seismic characteristics of active fault engineering site with the features of inhomogeneous, discontinuous, and multi-field coupling, to establish the numerical analysis method of tunnel seismic damage considering the interaction of lining and surrounding rock (fault), to exposit the seismic damage mechanisms and seismic response regularities of near-fault tunnel, to inspect the structural earthquake-resistant adaptability of near-fault tunnel. The results will provide theoretical and technical support for the design and construction of traffic tunnels in high seismic intensity near-fault area to improve the safety and reliability of these tunnels.

随着我国交通建设事业的快速发展，越来越多的隧道将不可避免地建于高地震烈度近断层区域。近断层隧道的震害最为严重，其震害机理与地震响应特征亦有别于远场隧道。本项研究基于近断层隧道的场地特点，利用理论分析、数值模拟、模型试验等综合手段，研究活动断层工程场地粘、蠕滑效应及影响要素、近断层隧道衬砌-围岩互制作用的地震破坏机理、近断层隧道结构抗减震性能等隧道建设中亟需解决的问题。通过研究，以期探明非均匀、非连续、多场耦合的活动断层工程场地地震特性；建立考虑衬砌-围岩（断层）相互作用的隧道地震损伤破坏数值分析方法；揭示近断层交通隧道的震害机理及地震响应规律；检验近断层隧道结构抗减震适应性。研究成果可为高地震烈度近断层交通隧道的设计和施工提供理论和技术支撑，提高隧道的安全性和可靠性。

随着我国交通建设事业的快速发展，越来越多的隧道将不可避免地建于高地震烈度近断层区域。近断层隧道的震害最为严重，其震害机理与地震响应特征亦有别于远场隧道。由此，本课题结合理论分析、数值模拟以及振动台模型试验等研究手段，着力研究了以下问题：断层粘滑过程以及衬砌震害机理；穿越断层破碎带隧道地震响应规律；隧道抗减震措施以及关键设计参数。采用数值模拟手段，获得了不同围岩条件下逆断层、正断层和走滑断层三种类型断层在粘滑过程中的加速度、速度和位移时程曲线；通过对不同围岩条件下三种类型断层粘滑时衬砌开裂损伤过程的探索，揭示了不同围岩、不同类型断层下衬砌与围岩之间互制耦合作用的衬砌开裂损伤过程和衬砌结构震害机理；利用振动台模型试验和数值模拟对穿越断层破碎带隧道的地震响应规律进行了系统讨论，并对隧道设置隔震层、抗震缝、断层破碎带围岩加固、隧道扩挖、隧道铰接等相关措施的抗震效应进行了合理评价，提出了针对不同措施的关键设计参数，研究成果可为高地震烈度近断层交通隧道的设计和施工提供参考，提高隧道的安全性和可靠性。