TBM自重对围岩变形影响的数值模拟研究

Research on Numerical Simulation of the Influence of TBM Self-weight on Surrounding Rock Deformation

为研究双护盾全断面隧道掘进机(TBM)自重对围岩变形的影响,基于FLAC3D有限差分软件,通过改变隧道的埋深与围岩条件,建立3种工况数值模型,并对每个工况分别进行了考虑TBM自重与不考虑其自重的数值模拟,以对比各种工况下有无TBM自重作用的隧道围岩纵向位移曲线(LDP曲线);研究了TBM自重对围岩变形的影响。模拟结果表明,TBM自重可抑制隧道围岩的径向位移,并随着开挖隧道的围岩等级升高、埋深变浅,其自重对围岩变形的影响越大,且与不考虑TBM自重的围岩变形相比,边墙洞壁的径向位移减小率最大,仰拱与拱顶次之。这些认识对研究TBM与围岩的相互作用和预测卡机有重要意义。

In order to study the influence of TBM self-weight on the deformation of surrounding rock,this paper establishes three numerical models by changing the depth of tunnel and surrounding rock conditions,based on FLAC3 Dfinite difference software. The numerical simulation of considering TBM self-weight and not considering its gravity is carried out in each working condition. By comparing the LDP curves with and without TBM gravity under various working conditions,the influence of TBM self-weight on surrounding rock deformation is studied. The simulation results show that TBM selfweight can restrain the radial displacement of tunnel surrounding rock,and with the surrounding rock grade increasing,the buried depth becomes shallow,the influence of TBM self-weight on the deformation of surrounding rock is greater.Compared with the surrounding rock deformation without considering TBM gravity,the radial displacement reduction rate of the side wall is the largest. These understandings have important significance for the study of the interaction between TBM and surrounding rock and for predicting TBM entrapment.