胶结土体中地铁隧道近正断层破坏机理研究

With the development of subway system, more and more tunnels are constructed in seismic active zone and are subjecting to potential normal faulting. Systematic studies are necessary to understand the deformation mechanism of tunnel induced by normal faulting in cemented soil. This is critical for better design of tunneling. In this study, centrifuge and numerical modeling are both conducted to investigate the interaction of cemented soil and tunneling during normal faulting. The influences of pre-existing fracture and its tip location on additional stresses around lining and tunnel deformations are studied. Parametric studies on the distance between tunnel and bedrock fault are also carried out. In addition to the subway tunneling, this study also throws light on the understanding and design of other underground structures subjecting to faulting.

地铁隧道建设飞速发展，不可避免地会穿越地震活跃带并遭受基岩正断层错动的威胁。针对正断层错动引起胶结土体中隧道变形破坏这一课题的系统研究相对缺乏，相应的抗断层错动设计理论已成为地铁隧道建设迫切需要解决的问题。本项目通过离心机实验和数值模拟等方法，研究基岩正断层错动引起的胶结土体与地铁隧道相互作用机理。并考虑胶结土体中存在的隐伏裂缝及其上断点埋深，隧道同基岩正断层之间相互位置关系等因素，对隧道结构附加应力和结构变形所产生的影响。该课题不仅对地铁隧道，还对其它地下结构抗断层错动设计的发展和完善也起到积极推动作用。

地铁隧道建设飞速发展，不可避免地会穿越地震活跃带并遭受基岩正断层错动的威胁。针对正断层错动引起上覆土体中隧道变形破坏这一课题的系统研究相对缺乏，相应的抗断层错动设计理论已成为地铁隧道建设迫切需要解决的问题。本项目通过土工室内试验、小尺寸物理模型试验、土工离心机实验、数值模拟和理论推导相结合的方法，研究基岩正断层错动引起的上覆土体与地铁隧道相互作用机理。重点分析隧道结构的变形和受力特征。详细分析了不同隧道相对刚度、不同隧道埋深、不同土体特性等关键因素的影响规律。针对各个关键影响因素提出了无量纲组，并建立了一个可预测隧道变形加固范围的理论计算模型。该课题不仅对地铁隧道，还对其它地下结构抗断层错动设计的发展和完善也起到积极推动作用。