地下洞室碎裂结构围岩稳定性二维有限元数值模拟

以西北地区某市水利地下洞室工程为例,通过分别建立的Ⅲ类、Ⅳ类和Ⅴ类围岩的3个计算模型,对处于低地应力状态下地下洞室碎裂结构围岩,开挖后围岩变形破坏、变形破坏区分布与围岩稳定特征,采用了二维弹塑性有限元法进行了数值模拟、评价。模拟与评价结果表明:研究区洞室开挖后,洞室顶部与侧壁围岩均形成不稳定的变形破坏区,但以洞顶位置围岩所形成的破坏区最具规模,该特征与现场洞室围岩位移监测结果基本符合。该项研究所取得的成果不仅具有重要理论价值,而且对于确保研究区地下洞室工程建设的圆满进行具有实际指导意义。

2D FEM SIMULATION FOR THE STABILITY OF SURROUNDING ROCKMASS WITH CATACLASTIC TEXTURE OF UNDERGROUND EXCAVATION

A hydraulic engineering project of a city in the northwest of China is taken as an example in the paper. It made three calculating models for the rockmass types which had been named as rock mass Ⅲ、Ⅳ and Ⅴ and it adopted 2D-elastic-plastic finite element method to simulate the stability of surrounding rockmass in low ground stress region. The simulated result shows that deformation and failure zones would be formed at the arch and both sides of excavation, but the failure zones formed at the arch of excavation are especially more serious than those at both sides.The achievement of this research will play a very important role in making progress in underground engineering projects.