复合土钉墙支护效果数值模拟

以济南市西客站基坑工程为依托背景,选取具有代表性的2-2支护剖面和2-2加强段支护剖面进行分析,在修正剑桥模型的基础上,利用摩尔库伦准则,通过FLAC^3D有限差分软件对简单土钉墙和复合土钉墙(CSNW)进行数值模拟。其中,物理参数的选取、监测点的布置、最大不平衡力的精度、初始条件、边界条件的确定等均满足计算精度的要求。通过两种支护形式计算结果的对比分析,验证了复合土钉墙在控制边坡水平位移方面较简单土钉墙具有一定的优越性,分析了土钉和锚索的受力机理,预测了潜在滑移面的大致位置;结合基坑变形曲线,预测了可能发生滑坡的位置,提出了防治建议。

Numerical Simulation of Composite Soil Nailed Wall

Based on the foundation pit project of Jinan’s West Railway Station,the finite difference software FLAC3D is used to do numerical simulation of normal soil nailed wall and composite soil nailed wall(CSNW).The normal soil nailed wall is represented with 2-2 support elements and CSNW is represented with 2-2 support-enhanced elements.They are both simulated with Modified Cam-Clay Model and Mohr Coulomb’s criteria.The numerical results by FLAC3D show that the selection of physical parameters,arrangement of monitoring points,the precision of unbalanced force,initial condition and determination of boundary conditions are satisfied correctly.Through the comparison,it has been verified that CSNW is more effective in controlling the displacement of the slope.This paper also analyses the loading mechanism of soil nail and anchor cable and predicts the position of the possible slip plane.Combining the calculated deformations of the foundation pit,this paper has given prediction before the slope slips and the method to prevent it.