土钉墙支护技术的数值模拟分析

Numerical Simulation Analysis of Soil-nailing Walls Support

土钉墙支护是粉砂土、黏性土等地区基坑开挖支护的主要形式之一。采用ABAQUS有限元分析软件建立数值模拟模型,土体建模应用Mohr-Coulomb本构模型,土钉与土体间采用内置区域约束。在放坡开挖时考虑有、无土钉墙支护的两种工况,开展边坡支护前、后的变形及稳定性分析。计算结果表明,放坡开挖安全性远大于竖直开挖;放坡开挖基坑边缘最大水平位移发生在中下部,在开挖深度90%处;土钉轴力两头小中间大,土钉的设置也能有效延缓边坡塑性区贯通。

Soil-nailing walls is main support structure in silty and clay soils.Calculated models are set up on the basis of ABAQUS FEM software by applying soil constitutive model of Mohr-Coulomb and embedded region constraint between soil and soil-nailing.Considered two conditions with and without soil-nailing walls support during sloping excavation.Analyzed the deformation and stability before and after support.The results show that the safety of sloping excavation is greater than vertical excavation;the maximum horizontal displacement of the edge occurs in lower parts,at the excavating depth of 80%;the axial force of soil nails is small at both ends and large in the middle.The setting of soil nails can also effectively delay the breakthrough of the plastic zone.