高陡边坡有限元强度折减法分析

Analysis on High Steep Slope by FEM Strength Reduction Method

针对毕家尖高陡边坡稳定性问题,通过建立边坡三维几何模型、网格划分、边界条件、岩体力学参数的确定等,对边坡开挖过程稳定性进行了模拟。采用摩尔-库伦强度准则,并利用有限元强度折减法得出塑性区分布、位移、安全系数等。计算结果表明,开挖过程中边坡内部应变应力集中存在于软弱夹层中,该区域安全系数略大于1,属于欠稳定-不稳定状态,需要对软弱夹层区域进行加固治理;开挖对毕家尖边坡整体稳定性影响较小,安全系数大部分处于1.3以上,边坡整体上较为稳定。

Aimed at the stability problem of high and steep slope in Bijiajian, the stability of slope during excavation was simulated by establishing the 3D geometry models, meshing division, setting boundary conditions, setting mechanical parameters of rock mass and other methods. By using the Mohr-Coulomb strength criterion and the FEM strength reduction method, distribution, displacement and safety factors of the plastic zone were obtained. The results showed that the strain and stress of the slope was concentrated in the weak interlayer during excavation. The regional security factor was slightly greater than 1. It showed that the region was in a less understable-unstable state and the weak interhedded region should be strengthened. The excavation had little effect on the overall stability of slope in Bijiajian, the safety factors were mostly above 1.3, and the slope was generally stable.