基于FLAC3D的深基坑支护三维数值模拟分析

Three-dimensional numerical simulation analysis of deep foundation pit supporting based on FLAC3D

为研究基坑不同支护方式对围护结构变形及稳定性的影响,利用FLAC3D三维快速拉格朗日差分方法对某地铁深基坑分步开挖与支护进行数值模拟,并对两种支护方案进行对比分析。研究结果表明:地下连续墙最大水平位移出现在墙顶,且位于地下连续墙长度方向的中部;在分步开挖时,第一步开挖时地下连续墙的位移变化率与第二步开挖时的位移变化率相同。研究还发现,采用地下连续墙加内支撑的支护方案对地下连续墙的侧向位移有较明显的抑制作用。

To study the influence of different supporting methods of foundation pits on the deformation and stability of a retaining structure, FLACdD was adopted to conduct a numerical simulation on the stepwise excavation and support of a certain subway deep foundation pit, accompanied with comparison of two supporting schemes. The results show that the maximum horizontal displacement of the underground diaphragm wall appears at the top and the center along the length of the wall. Moreover, the displacement rate of the wall in the first-step excavation is the same as that of the second-step. It is also found that the inhibitory effect of lateral displacement of the underground diaphragm wall is relatively obvious when the wall is internally supported as adopted in one supporting scheme.