基于应力比的偏压隧道施工工法及顺序研究

浅埋偏压隧道施工工法及开挖顺序的合理选择，直接影响隧道周边围岩及支护结构的安全性。以回头沟隧道浅埋偏压段右幅进口段为工程依托，运用MIDAS/GTS软件进行二维数值模拟，通过对台阶法、单侧壁导坑法、环形开挖留核心土法、CRD法等不同施工工法下控制点Von Mises应力比的对比分析，及单侧壁导坑法、CRD法等不同工法在不同开挖顺序下控制点Von Mises应力比的对比分析，研究Von Mises应力比是否可以作为比选施工工法和开挖顺序的指标。

Study on Construction Method and Excavation Sequence of Bias Tunnel Based on Stress Ratio

Reasonable selection of construction method and excavation sequence of shallow-buried bias tunnel directly affects the safety of the surrounding rock and the supporting structure. In relation to the right entrance of the shallow-buried bias section of Huitougou Tunnel, two dimensional numerical simulation was carried out with MIDAS/GTS software, and then the Von Mises stress ratio of the reference points not only under step cut method, single side drift method, core-keeping ring cut method, CRD or other construction methods but also under different excavation sequences, were compared and studied, so as to study whether the Von Mises stress ratio can be chosen as the index of selection of the construction method and excavation sequence.