| With the development of the national economy, large amounts of various tunnels and underground structures have increasingly being built, their scale is extending continuously. Underground structures have been utilizing widely in energy sources, traffic, city construction defending engineering, etc. So their importance is more visible. Especially civil air defense underground structures have important effects on the civil air defense and national stability when once earthquake occur. Therefore, anti-seismic of underground structures is important both in theoretical research and engineering.Rational numeration model with viscous-elastic artificial boundary condition is proposed according to dynamic FEM. This paper analyzes seismic response of underground structures by ANSYS. Using the unconditionally stable implicit Newmark time integration algorithm, the effects of some key factors such as buried depth, difference seismic wave and the earthquake excitation orientation are studied. The results show that dynamic response of structure is considerably affected by the thickness of overburden layer, and also dynamic response of structure havoc by difference seismic wave.Finally, this paper cites an example to provide the scientific base for the design underground structure. Under the seismic analysis, at the top of structure, the stress, strain and acceleration are bigger than other points, from the points of the whole structure, the top of structure and corners of the station are very incidental to be destroyed. As a result, in the course of designing and construction, more attention should be paid to them.Furthermore, calculation is carried out to underground structures on nuclear explosion load by quasi-static load method. By analysis, it is discovered that the load on roof is far more than the one on the side wall and the ratio of impact load on roof is also more than the one on the side wall. Roof is more dangerous than the side wall and attention should be paid to it. |
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