隧道开挖步距对地层位移影响研究

Study on Influence of Excavation Space on Soil Displacement of Undercutting Tunnel

以深圳地铁暗挖隧道施工资料为基础,利用三维模拟程序对暗挖隧道施工过程及支护结构进行了模拟分析。对于喷射混凝土和格栅钢架组成的隧道初支系统,考虑了喷射混凝土的时间效应及格栅钢架与喷射混凝土的不同刚度。在模拟过程中,研究了不同开挖步距对地层位移的影响规律。从分析结果可以得出,隧道拱顶沉降和地表沉降随着开挖步距增加而增大,其沉降与开挖步距近似服从二次多项式的函数关系。

Using three-dimensional simulation program, construction and supporting system of undercutting tunnel is simulated and analyzed based on Shenzhen metro tunnel documents. For tunnel initial supporting system composed with shotcrete and steel grid frame, time effect of shotcrete and different rigidity between shotcrete and steel grid frame is considered. In the simulation process, Influence law of different excavation space on displacement is studied. From the result of analysis, arch crown and surface settlement is increase as the increase of excavation space. The settlement with excavation space is submitted to quadratic equation.