平行褶皱构造对隧道围岩变形的影响研究

Study on the Influence of Parallel Fold Structure on Deformation of Tunnel Surrounding Rocks

岩层受力弯曲变形形成褶皱构造,隧道穿越褶皱地质构造时,在复杂地质构造及地应力条件影响下,隧道围岩容易发生变形破坏,影响隧道的稳定性。针对隧道在平行于褶皱轴线穿越平行褶皱构造地质时的围岩变形问题,文章采用有限差分法并结合实际工程中褶皱构造的隧道围岩进行了数值模拟计算,探究了隧道围岩的变形规律,提出了控制围岩变形的思路。结果表明,隧道在平行于褶皱轴线穿越平行褶皱构造时,拱顶及仰拱部分更容易发生变形破坏,且主要集中在软弱岩层部分及软硬岩层分界面处,具体为向斜类型的软弱岩层上分界面和背斜类型的软弱岩层下分界面处,因此可考虑采用加强拱顶及仰拱围岩的位移控制,加固处理平行褶皱构造中的软弱岩层部分来减小隧道围岩变形的控制思路。

Bending deformation of rock strata occurs due to force and fold structure is formed thereof,further it is lia⁃ble to have deformation failure of tunnel surrounding rocks under influence of complex geological structure and geo⁃stress,affecting tunnel stability.Aiming at the surrounding rock deformation of tunnel which is parallel to fold axis and passing through fold structure geology,finite difference method is adopted to conduct numerical simulation and calculation,to explore the deformation law,and to put forward the thought of deformation control of tunnel surround⁃ing rocks.The results show that deformation is more likely to occur at tunnel crown and invert and mainly concen⁃trated in the soft rock stratum and the soft-hard rock interface when the tunnel passes through the parallel fold struc⁃ture with being parallel to the fold axis,specifically they are at the upper boundary of synclinal soft rock stratum and the lower boundary of anticlinal soft rock stratum,and it is considered to control deformation at tunnel crown and in⁃vert and to reinforce the soft rock stratum of parallel fold structure to reduce the deformation of tunnel surrounding rocks.