山体偏压影响下地铁基坑开挖变形规律研究

Research on the Deformation Law of Subway Foundation Pit Excavation under the Influence of Mountain Bias

为了研究山体偏压对地铁基坑开挖过程中变形的影响,本文利用FLAC 3D 5.0数值软件建立了考虑山体偏压的基坑开挖数值计算模型,分4步开挖了地铁深基坑,分析了山体偏压影响下的地铁深基坑变形规律,研究山体偏压作用对地铁深基坑变形特性的影响。研究结果表明:地铁深基坑周边土体的沉降值、水平位移值和剪应变均随基坑开挖深度的增大而增大,山体边坡整体稳定安全系数随之逐渐降低。与无山体偏压对比,山体偏压作用下坡体的最大沉降值、围护墙体的最大水平位移均较大,不利于基坑的安全稳定控制。

In order to study the influence of mountain bias on the deformation of subway foundation pit excavation, FLAC 3 D 5.0 numerical software is used to establish a numerical calculation model of foundation pit excavation considering mountain bias, and the subway deep foundation pit is excavated in 4 steps.The deformation law of subway deep foundation pit under the influence of mountain bias is analyzed, and the influence of mountain bias on the deformation characteristics of subway deep foundation pit is studied.The research results show that the settlement value, horizontal displacement value and shear strain of the soil around the deep foundation pit of the subway all increase with the increase of the excavation depth of the foundation pit, and the safety factor of the overall stability of the mountain slope gradually decreases.Compared with no mountain bias, the maximum settlement value of the slope and the maximum horizontal displacement of the retaining wall under the action of the mountain bias are larger, which is not conducive to the safety and stability control of the foundation pit.