软弱围岩条件公路连拱隧道施工方法数值分析

NUMERICAL SIMULATION ANALYSIS ON THE CONSTRUCTION METHODS OF A MULT-ARCH ROAD TUNNEL IN WEAK SURROUNDING ROCKS

针对软弱围岩条件(IV级围岩)大跨度连拱隧道施工安全和围岩稳定问题,结合工程实际,采用非线性有限元法,对连拱隧道施工过程进行了数值计算分析,对比了中导洞-核心土和三导洞先墙后拱施工工艺下隧道的位移特征、点安全系数、二次衬砌应力、锚杆和钢拱架轴向应力。实际工程研究表明,中导洞-核心土施工工艺开挖软弱围岩条件大跨度公路连拱隧道是可行的,对类似软弱围岩条件的隧洞施工有一定参考价值。

The Construction safety and rock mass stability of shallow multi-arch tunnel in weak surrounding rocks are very critical in projects. Based on a multi--arch road tunnel, the nonlinear Fern is used to study the displacement, point safety fac- tor, lining stress, stress of bolt and steel arch beam in the process of construction under two typical construction plans, inclu- ding first center leading tunnel and then key rock soil construction plan, first center leading tunnel and then two sidewall leading tunnel construction plan. The computational results indicate that center leading tunnel key rock soil construction plan used in the excavation of multi-arch tunnel in weak surrounding rocks is feasible, which provide a guide for the construction of tunnels in similar weak Surrounding rock.