小净距隧道三维动态施工分析

Three-dimensional Dynamic Analysis of Construction of Tunnel with Small Clear Distance

结合湖北宜巴高速公路峡口隧道的施工,利用FLAC-3D软件对小净距隧道施工过程进行三维弹塑性模拟计算,重点分析采用台阶法和中导洞超前法施工时左右洞掌子面的距离对隧道围岩和支护的力学影响;得到了在掌子面掘进过程中,围岩和支护结构的受力及变形随纵向开挖进尺的变化规律,对小净距隧道在纵向影响因素作用下的施工力学特征有了初步认识,可为类似工程提供有益参考。

Combined with the construction of Xiakou tunnel of Yiba Expressway in Hubei Province, FLAC-3D software was used to simulate the construction process of tunnel with small clear distance. The mechanical effects of the distance between the left and right face of the tunnel on the surrounding rock and the support of the tunnel during the construction by bench method and pilot tunnel method were analyzed emphatically. The variation law of the force and deformation of the surrounding rock and the supporting structure during the excavation process with the longitudinal excavation was obtained. A preliminary understanding of the mechanical characteristics of the tunnel with small clearance impacted by the longitudinal influencing factors was achieved, which can provide a useful reference for similar projects.