| With the rapid development of the state high grade construction, there are more and more highway tunnels, especially large-span highway tunnels. In the course of the highway tunnel's construction, the stress in rock mass will redistribute around ground. When this kind of stress exceeds surrounding rock's ultimate strength, surrounding rock will lose its stability and destruct. Consequently, it becomes increasingly important for the study of tunnel-surrounding stability and its forced condition of the structure during the construction of highway tunnels.In this paper, by taking Yunyangshan tunnel engineering as an example, and combining qualitative evaluation and quantitive evaluation as well as overall evaluation and part evaluation, a comprehensive study on tunnel-surrounding stability is developed, in order to make a foundation to evaluate it. Firstly, the stress and strain specialities on construction process of tunnel-surrounding and the shoring mechanism are thoroughly studied, in order to form proper evaluation principles of tunnel-surrounding stability. Secondly, by studying the mechanical parameters of sundounding rock, a feasible method to compute them is put forward. This method's process is computing the mechanical parameters from the TSP203 system. Finally, by thoroughly analyzing the three-dimension plasticity finite-elements, introducing the procedure of plasticity finite-elements method in detail, and using ANSYS9.0 to perform a modeling to the surrounding rock of Yunyangshan tunnel, the change rules of the surrounding rock and the shoring's displacement, stress and strain, and the radiation area of anchor rod are educed. Therefore, the sundounding rock's overall stability is evaluated in order to direct construction. |
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