相邻桩锚基坑开挖变形相互影响数值分析

以两个相邻桩锚支护的基坑工程为实例,基于小应变硬化土(HSS)模型,通过Z-Soil岩土有限元分析软件建立数值计算模型,分析相邻基坑开挖对基坑变形的影响.分析结果表明:相邻桩锚基坑开挖明显减小排桩桩顶水平位移、排桩深层水平位移、坑间土体深层水平位移和坡顶水平位移,对于桩顶水平位移的影响最为显著;相邻桩锚基坑开挖也增大坑间地表沉降,产生的沉降接近两个单坑引起的沉降叠加,最大沉降位置出现在两基坑的正中央;相邻桩锚基坑的支护设计宜考虑相邻基坑开挖的影响,宜以变形不超过单坑开挖产生的水平位移为控制基准.

Numerical Analysis of Interaction of Adjacent Pile-Anchor Foundation Pits Excavation Deformation

Taking two adjacent pile-anchor foundation pits with pile-anchor supporting as engineering examples, base on the hardening soil model with small strain model(HSS), the numerical calculation model is established using Z-Soil geotechnical finite element analysis software, and the influence of adjacent foundation pits excavation on deformation is analyzed. The analysis results show that the excavation of adjacent pile-anchor foundation pits significantly reduces the horizontal displacement of pile top, row-pile deep horizontal displacement, soil deep horizontal displacement between pits and slope top horizontal displacement, especially the effect of pile top horizontal displacement. The ground settlement between pits also increases, is approximately equal to the superposition of the two settlements due to single pits, and the maximum settlement position appears in the center of the two foundation pits. The influence of the adjacent foundation pits excavation would be considered in the design of supporting of the adjacent pile-anchor foundation pits, and the horizontal dis-placement due to the single pit excavation should be taken as the control value for the second foundation pit.