| With the rapid development of the large-span tunnels and underground structures, the researches of reasonable construction method and the seismic response analysis of such structures are of great social and economic effect. Therefore, in the engineering background of the longtoushan tunnel, this paper makes a thorough and analytical study of the different construction methods and the seismic dynamic response of the four-lane road tunnel. The concrete research is as follows:Firstly, the viscous boundary and viscous-spring boundary are introduced in detail, and the simple achieved access in finite element software of them is also given.Secondly, the construction methods of different grade surrounding rock are simulated. In addition, the tunnel mechanical behavior and stability are studied. It is shown from analysis that the double side drift method and CD method are superior to the others for surrounding rock grade V, and bench method for surrounding rock III is considered to be the reasonable one. At the same time, it is verified the credibility of the numerical calculation through field test.At last, based on the viscous-spring boundary and the finite element method for soil-structure interaction problems, a three-dimensional analysis model is presented. Furthermore, the author analysis the displacement, stress and supporting internal force dynamics response in the seismic force by different kinds and directions of earthquake, different kinds of surrounding rock conditions and boundary conditions. Finally the conclusion has been drawn that the greatest response occurs on the crown when the seism enspirits in horizontal direction, and on the sidewall when in vertical direction. The spring stiffness of viscous-spring artificial boundary has important effect on accuracy of result, and the displacement and stress response of lining structure become larger as the gradually decrease of surrounding rock's grade. |
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