开挖卸荷条件下高边墙岩体变形和破坏的数值计算

Study on high side wall deformation stability of a large-spaned underground powerhouse

对高边墙的稳定性研究 ,除了受结构面控制的局部块体稳定性外 ,最为重要的问题是直立高边墙在地应力作用下 ,其弹塑性变形及由此而引起的边墙应力环境条件恶化所导致的破裂问题 ,这类问题可统称之为弹塑性变形稳定性 ,对这类问题的分析目前主要采用的是基于弹塑性理论的有限单元法数值模拟 ,且以二维分析为主。本文针对某地下电站工程较为复杂的岩体结构特征和地下空间形态 ,采用三维弹塑性有限元单元法模拟了随着地下厂房开挖的进行 ,高边墙岩体变形破坏的动态演化序列 。

About high side wall stability, the most important question is elastic plastic deformation and failure besides local block stability controled by discontinuities. These questions can be called elastic plastic deformation stability. Now analysising these questions mainly uses finite element numerical modeling based on elastic plastic theory and the modeling is mainly two dimensional finite element method. In view of the complex structure of rock mass and space shape of this underground engineering , this paper applied three dimensional elastic plastic finite element numerical modeling technique to simulate the caving process of an underground powerhouse . Deformation and breaking development array of rock mass in high side wall is studied following the caving process. deformation stability condition of high side wall is evaluated