| At present, with the rapid development of the construction of high quality highway, thereare more and more various forms of highway tunnels. During the excavation of the tunnel,there are always a variety of problems, especially the problem of the stability of surroundingrock and the displacement and deformation of the supports due to the geology condition andthe complexity of tunnel itself. The stability of surrounding rock and supports is an importantindex for the evaluation of highway tunnel designation and construction. Also, this stability isa guarantee for promoting the development and the safe use of highway tunnel. So, it isnecessary to further the study.This paper is based on the reference to related papers. Combined with the qualitative andquantitative, it analyzes the stability of surrounding rock and supports during the excavation.Firstly, it theoretically formulates the judgment criterion of the surrounding rock stability andthe failure mode of the surrounding rock. Secondly, it introduces the basic principle of NATMbriefly. Then, combined with the monitoring measurement data, it analyzes the stability of thetunnel during the excavation, and analyzes the final convergence value by making theregression analysis for monitoring measurement data. Finally, it makes the numerical analysisfor the construction of Yan Shui，ao tunnel by the use of the finite element software (as, theMIDAS/GTS) with the method of elastic-plastic plane finite element. Then, it gets the law ofchanges of the displacement, stress and the plastic zone of the surrounding rock-supports bythe comparison of the result of the numerical simulation and the monitoring data. Thoughthere are gap between them, still the change trend is in consistent. And this indicates that themethod and the numerical model are reasonable. So, the calculation results can be the basisfor the tunnel optimization design and the construction plan, and it can be the reference to thesimilar tunnel construction in the future. |
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