大埋深引水隧洞穿越断裂带围岩变形规律研究

STUDY ON SURROUNDING ROCK DEFORMATION OF LARGE BURIED DIVERSION TUNNEL THROUGH FAULT ZONE

  • 摘要: 断裂带是深埋隧洞开挖过程中常见的不良地质现象。以滇中引水工程香炉山隧洞为工程背景,通过建立隧洞穿越断裂带的开挖数值模型,研究了隧洞拱顶、拱底、拱腰两侧的围岩变形规律,进一步分析了隧洞在穿越不同断裂带宽度、倾角、走向以及不同隧洞埋深工况下对围岩变形的影响。研究表明,由于断裂带区域的存在,围岩的垂直位移和水平位移发生了明显的改变,越靠近断裂带核心区域,隧洞拱顶、拱底和拱腰两侧围岩的变形越大,在断裂带中心区域附近围岩的变形达到最大值;围岩的垂直位移和水平位移随着断裂带宽度和隧洞埋深的增大而增大,随着断裂带倾角的增大而减小;断裂带走向的变化对围岩的垂直位移和水平位移影响较小。对于拱顶沉降,其综合因素影响程度从小到大依次为断裂带走向、断裂带倾角、断裂带宽度、隧洞埋深。

     

    Abstract: Fracture zone is a common bad geological phenomenon in the process of deep tunnel excavation. Taking Xianglushan tunnel of Central Yunnan Water Diversion Project as the engineering background, the deformation of surrounding rock on both sides of the arch, arch bottom and arch waist of the tunnel is studied by establishing the numerical model of tunnel excavation through the fault zone, and the influence of tunnel through different fault zone widths, dip angles, strike and buried depths on the deformation of surrounding rock is further analyzed. The results show that due to the existence of fault zone, the vertical displacement and horizontal displacement of surrounding rock change obviously. The closer the tunnel is to the core of the fault zone, the greater the deformation of surrounding rock on both sides of the tunnel arch, arch bottom and arch waist, and the deformation of surrounding rock near the center of the fault zone reaches the maximum value. The vertical and horizontal displacements of the surrounding rock increase with the increase of the width of the fault zone and the buried depth of the tunnel, and decrease with the increase of the inclination of the fault zone. The variation of fault zone strike has little effect on the vertical and horizontal displacements of surrounding rock. For vault settlement, the influence degree of comprehensive factors from small to large is the strike of fault zone, the dip angle of fault zone, the width of fault zone and the buried depth of tunnel.

     

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