软弱破碎带不同施工工法隧道围岩变形分析

依托中条山特长公路隧道,采用有限差分软件FLAC3D,对隧道开挖支护过程采用的不同施工工法下的施工过程进行了数值分析,对各工况下围岩变形规律进行了研究,研究结果表明:单侧壁导坑法施工拱底隆起与拱顶沉降的差值较小,可防止因拱底隆起过大而造成的隧道底板的破坏,核心土在维持掌子面稳定方面作用显著,在软弱围岩地层中台阶法与预留核心土法相比优先选用预留核心土法。

Analysis of deformation of tunnel with construction method in katamorphic zone

To research the deformation regularity of large section loess tunnel in construction procession with different construction methods,FLAC3 Dnumerical simulation is applied and the Zhongtiaoshan extra-long highway tunnel is taken as an example. Comparing deformation regularity of surrounding rock in different construction method conditions,the research results show that： the difference between invert uplift and vault settlement is small in single-side heading method construction,so it can prevent the arch of tunnel floor heave caused by excessive invert uplift. Core role in maintaining face stability is remarkable,step method in soft rock stratum preferred reservation core soil compared with reservation core soil method.