梅子沟联拱隧道中导洞锚喷支护FLAC模拟研究

梅子沟联拱隧道处于复杂的浅埋地层环境中,其穿越地层多数为强风化与全风化地层.根据联拱隧道动态设计施工的实质内容和新奥法施工原理,采用三维有限元差分法(FLAC)对梅子沟隧道中导洞锚喷支护设计进行了力学响应动态模拟,并分析了锚喷支护机理以及围岩体应力场和位移变形状况,由此提出了联拱隧道合理的施工工序.

FLAC Simulation of Shotcrete-Rock Bolt Support in Mid-guide Hole of the Meizigou Twin-Arch Tunnel

Twin-arch tunnels in soft rocks with small overburden,following NATM, cause great problems to all parties involved. The support of Meizigou tunnel was well monitored during its construction, though the rocks are strongly faulted. At the sometime,calculations of the propagation of the tunnel distressed zone and stress field around the tunnel, up to the surface, were performed by means of numerical model with the finite difference method. According to the quiddity of dynamic design, the FLAC is applied on the typical cross section of tunnel selected from actual twin-arch tunnel case to set up the three dimensional tunnel mechanics model. The FLAC^3D model and different support parameters are used to simulate and analyze the stress and displacement in the wall rock mass during shotcrete-rock bolt support. It not only offers theoretical foundation for the adiusting and simplifying of the construction procedure, but also good social economic benefits.