【摘要】 针对广惠高速公路小金口双连拱隧道在不同施工方法下围岩和隧道支护结构的力学问题,运用有限元的方法对三导坑开挖法和上下台阶开挖法进行了动态数值模拟,首次建立了在不同施工工序下围岩的应力场、位移场,进而对这两种施工方法进行了比较,得出采用上下台阶法开挖的方案较优。所建立的双连拱隧道支护结构体系内力(轴力和弯矩)模型,对双连拱隧道的设计和施工具有重大的指导意义。更多还原

【Abstract】 Based on the Xiaojinkou bi-arch tunnel engineering of the Guanghui(Guangzhou-Huizhou) highway, the paper studies the mechanics problem of the excavating and supporting during the bi-arch tunnel construction in the soft surrounding rock The excavating procedure of three heading and top and bottom benching has been simulated numerically by the finite element method(FEM) calculation The field of stress and displacement in the surrounding rock has been suggested firstly under the different order of the construction By comparison of the two methods, the scheme of top and bottom benching is much better than that of the three heading At the same time, the internal forces model (axel forces, bending moment and so on) of the support structure system of the bi-arch tunnel has been set up firstly The results have important guiding significance for the design and construction of the bi-arch tunnel更多还原