陡倾断层上下盘开挖引起地表变形的数值模拟分析

摘要

考虑地下开挖区与断层相对位置关系，采用简化数值模型对陡倾断层上下盘开挖引起的地表变形特征进行了数值模拟。结果表明，当断层位于地下开挖引起地表变形的压缩区且开挖区位于下盘时，地表出现不连续变形的可能性小；当断层位于地下开挖引起地表变形的压缩区且开挖区位于上盘时，随下向开挖进行地表断层处裂缝有减小趋势；而当断层位于地下开挖引起的地表变形拉张区时，断层出露处水平拉张明显，表现为拉张裂缝，随下向开挖深度增加、规模增大，不论开挖区位于上盘还是下盘，极可能导致地表出现正断层式的错动．%The ground deformation due to the relative position between the underground excavation and the fault was studied by the means of simplified numerical method. The results show that, when the fault located in the compressive region of ground surface incurred by underground excavation and the excavation in the footwalls, the likelihood of discontinuous deformation of the ground is tiny; when the fault located in the compressive region of ground surface incurred by underground excavation and the excavation in the hanging walls, the ground surface cracks where the fault located tend to get close ; when the fault located in the tensile region of the ground caused by underground excavation, the horizontal tension is so severe that there will be tension cracks where the fault outcrop exposed, the characteristics of normal fault slip will be displayed along with the mining depth and size increases, no matter the excavations lie in the hanging walls or in the footwalls.