客运专线超大断面隧道施工过程三维力学分析

Analysis of the 3D behavior of tunnels with super large cross-section on special lines for passengers during construction

客运专线上的隧道开挖断面积在150m2以上,必须选择合适的施工方法才能满足建设需要。对此,文章以Ⅳ级围岩为研究对象,根据隧道埋深的不同,对深埋情况下的台阶法和环形开挖留核心土法、浅埋情况下的CD法和CRD法等开挖方法进行了三维数值模拟;通过对超大断面隧道基本受力规律的分析比较,给出了适合于超大断面隧道的安全、经济、有效的施工方法。

The excavated cross - section of tunnels on special lines for passengers is more than 150 m^2 , so adequate excavation methods must be selected in order to meet the construction requirements. In this paper 3D simulations are carried out for bench excavation and ring cut method for deep overburden tunnels and for CD and CRD excavation methods for shallow tunnels respectively, the surrounding rocks are of grade Ⅳ. Safe, economical and effective excavation options adaptable for tunnels with super large cross-sections are recommended on the basis of the analyses of the behavior of this kind of tunnels during excavation.