TBM导洞扩挖法在高地应力软岩隧道施工中的应用效果分析

运用MIDASGTS有限元软件,分析了TBM导洞扩挖法在高地应力软岩环境中隧道开挖的应用价值。通过对某公路隧道分别采用TBM导洞扩挖法、预留核心土环形开挖法和两台阶法三种施工方法进行数值模拟,主要以拱顶沉降、拱腰水平收敛和拱底隆起等围岩变形指标进行对比分析,得出TBM导洞扩挖法高地应力软岩隧道施工时的围岩变形控制效果最好的结论。同时分析了在富水等复杂地质情况下,TBM导洞扩挖法在排水、探明前方地质情况等方面更具有优势。

Analysis on Application Effect of TBM Guiding Tunnel and Expanding Excavation Method in Highland Stress Soft Rock Tunnel Construction

In this paper, the finite element software MIDAS GTS is adopted to analyze the application value of TBM guiding tunnel and expanding excavation method in tunnel excavation in highland stress soft rock environment. Through numerical simulation for three construction methods (TBM guiding tunnel and expanding excavation method, reservation core soil annular excavation method and two-step method), main indicators of surrounding rock deformation like vault settlement, horizontal convergence of haunch and arched bottom uplift of surrounding rock deformation index were compared and analyzed, and the conclusion was obtained that the control effect of surrounding rock deformation by applying TBM guiding tunnel and expanding excavation method in highland stress soft rock tunnel construction is best. Meanwhile, under complex geological conditions like rich water, TBM guiding tunnel and expansion excavation method has more advantages in drainage, proven geological conditions in the front and so on.