关键词: 活断层, 位移模式, 隧洞, 蠕滑, 岩体力学特性分区

Abstract: The creep displacement of active faults has a great impact on the safety of tunnels, pipelines and other projects passing through these active faults. The displacement mode of active fault is the key basis for the design of structures crossing the fault zone. In response to this issue, the geological and active features of active faults are summarized. Based on that, the numerical simulation on faults-moving with different types and dip angles is carried out using the typical geological structure of the Yuanmou-Luzhi River active faults where the Fenghuangshan Tunnel of the Water Diversion Project in central Yunnan passing through. In the simulation, the zoning of rock mass mechanical parameters in the fault zone and creep time were taken into account, and the distribution characteristics of fault displacements along the tunnel axis under different conditions were analyzed. The results show: ① The horizontal and vertical displacement modes of reverse faults, normal faults and strike-slip faults are all "S" type, and the relationship between the displacement modes and fault dip angle is not significant. ② The gradient of creep displacement is closely related to mechanical properties of rock mass. ③ The displacement modes of fault creep are affected by the zoning of the mechanical properties of fault zone rock masses, and the mode of the displacement is "Z" type when the fracture zone is homogeneous and not the same as the influence zone.④ Localization problems of normal faults and reverse faults displacement modes occur with creep time. The displacement modes of strike-slip faults don’t change with the creep time. The results of the study will provide important references for the design of tunnel engineering structures passing through active faults.

Key words: active fault, displacement mode, tunnel, creep, zoning of rock mechanical properties