单洞双层隧道围岩力学特性分析

The Mechanical Property of Surrounding Rock about Single Cavern and Double Layer Tunnel

单洞双层隧道作为一种新的隧道形式,不同于分离式隧道和连拱式隧道。用大型通用有限元软件ANSYS,对单洞双层隧道和分离式隧道开挖后的情况进行了数值模拟。分析开挖后围岩的应力和位移变化情况和塑性区分布,通过对比得出在浅埋情况下,两种隧道围岩应力和位移分布基本一致,地表沉降和分离式隧道相当,隧道对围岩扰动深度较大,边墙是其薄弱部位,应力松弛明显,水平位移较大,塑性区水平方向分布较大。

The single cavern and double layer tunnel as a new structure form, is different from the separated tunnel and double - arch tunnel. Using the general - purpose finite element software ANSYS, the condition of the surrounding rock is simulated by numerical simulation after the excavation of the single cavern and double layer and separated tunnel. The change of plastic zone, displacement and stress of surrounding rock were analyzed, and compared with those of different type of tunnel. The results show that displaement and press of single cavern and double layer tunnel is approximately the same to the separated tunnel in low depth, and the sedimentation is approximately equal; The single cavern and double layer tunnel has more influence on the surrounding rock, especially the sidewall is a danger area, and stress relaxation, horizontal displacement and the distribution zone are larger.