| Anisotropy is an important feature of rock mess structure. The layered rock mess in the tunnels and underground engineering always display obvious transverse anisotropy, which have a significant effect on the deformation of the surrounding rock and stress distribution state. Considering the extensiveness of layered rock mess, based on Gonghe Tunnel Project (ie, Pengshui-Wulong expressway tunnel, which belongs to Chongqing to Changsha Provincial Expressway), this paper discusses the anisotropy of layered rock mess. By means of laboratory experiment, theoretical analysis and numerical simulation, the structure features, strength and deformation characteristics of layered rock material are studied. The influence of anisotropy in layered rock mess on the tunneling and underground excavation is also discussed. The main research contents of this paper are as follows:(1)The anisotropy of layered rock is studied based on its structure characterizes. The strength characterizes and failure behaviors as well as its influence factors of layered rock are also discussed.(2)Laboratory tensile and compression tests are made on the shale samples from construction site, whose results provide basic mechanical parameters. Stress-strain relationship, strength and deformation characterizes of Shale which shows typical layer structure are studied. It lays a good foundation for the stability analysis of tunneling and underground excavation in layered rock mess.(3)Finite elements analysis methods and process of layered rock mess are summarized based on its anisotropy.(4)Numerical simulation software ANSYS is used to analyze the stability of tunnel with layered surrounding rock. With the numerical results, the effect of transverse anisotropy on the deformation and stability of surrounding rock is studied. According to stress-strain relationship and strength characterizes from laboratory results, deformation characterizes and stress distribution of surrounding rock with different active support are studied.
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