| China has a vast, complex geological structure, which has a layered structure of sedimentary rocks accounted for 77.3 percent of China’s land area, and accounted for 66.6% of the world’s land area. Depending on the tilt angle of the rock, which can be divided into dipping, steep, steep and erect four layered intrusions. Because of this remarkable rock characteristic layered structure, leading to its structural deformation and strength properties also have significant anisotropy, the failure mode and mechanism of layered rock mass was significantly different from other rock. In addition, in the construction field often encounter a lot of layered rock mass stability related issues, therefore, the study of the stability of layered rock tunnel excavation and other issues is particularly important.Based on the theoretical research, and aid of FLAC3 D numerical simulation software for different inclination layered rock tunnel stability and supporting effect in layered rock bolt research, the results of the study provide a layered rock tunnel stability analysis and design of structural bolting experience, it also saves money, get good economic returns.The main contents of this study can be divided into the following areas:First of all, access to relevant literature on the mechanical characteristics of layered rock, constitutive models and failure criteria summarized, identifying research ideas of the article, and then get the failure mechanism and the layered rock tunnel can affect the stability of the main factors.Secondly, from the tunnel mixing unit discrete analog of the basic principles of law starting, with the establishment of numerical simulation software FLAC3 D model of layered rock tunnel different angle, which includes a non-level model,0 °, 22.5 °, 45 °, 67.5 ° and 90 ° of six models, for each model in rock stress, displacement, initial support of the mechanical characteristics, variation of the axial force of the bolt and the plastic zone were studied.Thirdly, from an economic point of view, respectively, 0 °, 45 ° two models, for example, the arrangement of the bolt, bolt length two suggestions for optimization of layered rock tunnel bolt. |
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