隧道穿越断层破碎带震害机理研究  

Seismic damage mechanism of tunnels through fault zones

作　　者：何川[1,2] 李林[1,2] 张景[1,2] 耿萍[1,2] 晏启祥[1,2] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《岩土工程学报》2014年第3期427-434,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划(973)项目(2010CB732105);国家科技支撑计划课题(2012BAG05B03;2013BAB10B04);国家自然科学基金高铁联合基金项目(U1134208);国家杰出青年科学基金项目(50925830)

摘　　要：首先对汶川"5.12"等各次大地震中跨越断层破碎带隧道震害进行了资料调研,然后通过振动台模型试验及数值计算对跨断层破碎带隧道的动力响应进行了研究,研究内容主要包括围岩与隧道结构的加速度响应特性、地层变形及衬砌结构内力分布规律等。分析结果表明:震害调研结果、振动台模型试验和数值模拟结果有较好的吻合性,穿越断层破碎带隧道在地震中易于产生破坏;隧道断层带段围岩有较大的加速度响应特性,加速度响应在断层接触段不连续;地震过程中断层带段隧道结构对地层具有明显的追随性和依赖性;断层带隧道错动破坏主要由断层带隧道围岩与较好段围岩位移不同步性而造成的位移差值引起,且位移差值与断层带和隧道较好围岩类型有关;隧道断层破碎带段与较好围岩段衬砌结构横断面具有基本相同的内力分布规律,衬砌内力在共轭45°方向最大,但断层破碎带段衬砌具有最大的内力峰值,更易于在地震过程中产生破坏等。以上成果对于合理认识跨越断层破碎带隧道的地震响应特征具有重要意义,可为隧道实际工程设计和施工的抗震设防提供宝贵的基础资料。First of all, a simple investigation into the responses of tunnels through fault zones during Wenchuan Earthquake and other major earthquakes is made. Then comparative analyses are carried out by means of shaking table model tests and numerical analyses, mainly on acceleration characteristics of the surrounding rock and tunnel structures, deformation laws of geological strata and distribution of internal forces and so on. The analyses indicate that the results of investigations, tests and numerical analyses are in good agreement and that the tunnels through fault zones are easily damaged. The acceleration response in fault contact segments is discontinuous, and the peak acceleration is obviously larger at the fault zones at the same elevation. The tunnel structure has little impact on the response of geological strata during earthquakes, and the behavior of the tunnel structure obviously adheres to and relies on geological strata in the fault zones. The tunnel dislocation damage mechanism is the relative displacement between the fault zone and the surrounding rock, and the relative displacement value is relative to the types of the surrounding rock. The tunnel cross-sectional structure in the fault zones has the same distribution characteristics of internal forces, that is, in conjugate directions of 45°, it is the greatest, but the tunnel structure has relatively higher internal forces and is easily damaged during earthquakes. Those findings are of great importance to the rational understanding of earthquake response behaviors of tunnels through fault zones, and they may provide precious data for the earthquake resistant design and construction of practical projects.

关 键 词：隧道工程 震害机理 断层破碎带 振动台模型试验 隧道地震响应特性 

分 类 号：U45[建筑科学—桥梁与隧道工程]