基于Hoek-Brown准则的开挖台阶长度力学特性研究

Study of the Mechanical Properties of Bench Length Based on the Hoek-Brown Criterion

文章基于Hoek-Brown屈服准则,采用有限元数值模拟方法对不同开挖台阶长度条件下的隧道施工过程进行了三维数值模拟,分析了隧道推进过程中横断面及地表位移响应规律。研究表明:随着台阶长度的增长,水平收敛量以及拱顶沉降量均将增大,开挖台阶长度分别为4 m,6 m,8 m和10 m时,相比于2 m台阶长度,其拱顶沉降量分别增长了9%,25%,29%和36%,水平收敛量分别增长了9%,12.5%,15.6%和25%;台阶长度对于开挖后主应力的变化影响较小,对于塑性区的影响也不是很大。

Based on the Hoek-Brown criterion,the tunnel construction process under different bench lengths was simulated with finite-element simulation,and the displacement response laws of the tunnel section and ground surface were analyzed.The results show that： the horizontal convergence and vault settlement increase with an increase of the bench length; compared with a bench length of 2m,the vault settlements increase by 9%,25%,29%,and 36%,and the horizontal convergences increase by 9%,12.5%,15.6%,and 25% with the bench lengths of 4m,6m,8m and 10m; and bench length has little effect on the principal stress and plastic zone after excavation.