边坡分级开挖过程应力变化特征分析

ANALYSIS OF STRESS VARIATION CHARACTERISTICS IN THE PROCESS OF SLOPE CLASSIFICATION

根据边坡地质条件,采用有限元软件建立计算模型,计算出第1级开挖边界上的初始应力并导出第2、……、n级开挖完成时的各阶段的应力场。通过模拟边坡分级开挖过程,得到边坡开挖前的最大、最小主应力等值线云图及边坡开挖后最大、最小主应力等值云线图,并给出了各级开挖对应开挖面关键部位的应力及各级高程开挖前后的主应力随深度的变化对比曲线。结果表明,开挖前,边坡岩体总体处于弹性,整体稳定性较好;开挖后,边坡开挖面的拉应力范围和量值有所增大;高程805～872m的边坡中上部浅表部岩体(约3.0m)应力降低明显,中上部高程开挖过程的锚杆参数需要加强,尤其是锚杆间距需适当缩小。

According to the geological condition of the slope, the finite element software is used to establish the calculation model, and the initial stress on the first stage excavation boundary is calculated and the second stress field at each stage of N level excavation. Through the simulation of slope excava- tion process, the slope before excavation, get maximum principal stress contour and after excavation, the maximum and minimum principal stress contour cloud line graph, and gives the corresponding levels of excavation excavation surface stress and elevation levels before and after the excavation of the principal stress changes with depth curves. The results show that the slope rock mass is elastic and the whole sta- bility isbetter. After excavation, the tensile stress range and the value of the slope face is increased. The rock mass （about 3.0m） in the upper part of the upper part of the slope with a height of 805 - 872m is reduced obviously, and the anchor parameters need to be strengthened in the middle and upper Gao Cheng excavation process.