基于济南西客站片区某深大基坑,利用有限元软件PLAXIS 3D强大的前处理和网格细化分功能,运用考虑土体加/卸荷作用的土体硬化本构关系,建立能够考虑基坑空间效应的三维整体有限元模型。通过数值模型的结果,详细地展现了排桩支护结构在不同施工阶段、不同平面位置处的位移和弯矩变化,同时着重分析了与坑角位置处相应值的对比;总结了桩后土体深层水平位移变化规律,显示出了明显的影响分区;并研究了内坑开挖中坑趾系数、内坑深度与内外支护结构间距比等因素对外坑支护结构产生的影响。对于超深超大基坑建立三维计算模型,考虑坑中坑开挖工况对基坑支护结构及周边环境影响,对于把握基坑整体工作机理,避免安全事故,精细基坑设计的整体布局和空间优化具有借鉴及参考意义。 Based on a deep foundation pit of Jinan West Railway Station Area, the finite element software PLAXIS 3D is used to deal with the strong pre-processing and meshing subdivision functions. The soil hardening constitutive relation considering soil loading / unloading is established. Three Dimensional Global Finite Element Model of Pit Effect. The results of numerical model show the displacement and moment variation of the piled piles supporting structure at different construction stages and different plane positions in detail. At the same time, the comparisons with the corresponding values ​​at pit positions are emphatically analyzed. The influence of the pit toe coefficient, pit depth and the ratio of the internal and external support structure spacing on the external pit support structure was studied. Considering the influence of pit excavation conditions on foundation pit support structure and the surrounding environment, it is necessary to consider the overall working mechanism of foundation pit, avoid the safety accident, the overall layout of the design of fine foundation pit and Space optimization has reference and reference significance.