大跨度拱形无柱地铁车站抗震性能分析

An Analysis of the Anti-Seismic Performance of a Large-Spanned Arch Metro Station with No Column Structure

采用土—结构相互作用原理针对我国首个明挖拱形无柱结构地铁车站———青岛地铁3号线保儿站进行了水平地震力作用下的有限元动力时程分析。结果表明，地震作用下地铁车站结构的动力反应较静力条件下的弯矩增幅在拱顶处最大，增幅率为42%；拱形结构和同跨度的矩形结构相比，在拱脚和边墙与底板连接处内力和变形都较大，在抗震设计时应特别注意加强这些部位的抗震措施；通过时程分析法可以看出在地震动0.1～0.9 s时，达到了结构的自振频率，地震动引起的地震反应最大，此频率点可以为地下结构反映谱的研究提供一定的参考。

The principle of soil-structure-dynamic-interaction （SSDI）is applied to the finite element dynamic time history analysis of the first open-cut non-columned arch metro station under the action of the horizontal seismic forces.The results show that the amplitude of the bending moment added of the subway station dynamic response under the earthquake condition,compared with that under the static condition,is the largest at the vault and the difference ratio is 42%.Moreover,compared with a rectangular structure,the internal forces and deformations of an arch structure of the same span are larger at the connections between the arch spring and the side wall and the floor.Therefore,it is necessary to pay greater attention to strengthening anti-seismic measures at these positions.Furthermore,it can be seen that,by means of the time history analysis method,the seismic motion reaches the frequency of the free vibration of the structure and the seismic response is maximum at the time period of 0.1～0.9 second after the earthquake happens.The frequency point may serve as a useful reference for the study of the reflection spectrum for underground structures.