采用不同隔震形式的双层地铁地下车站结构地震反应分析

Comparative analysis on seismic performance of two-story subway underground station structures with different isolating systems

针对地铁地下车站结构中柱、中板等抗震薄弱构件,分别研究了车站结构在传统完全约束结构形式下,在上下层中柱顶部设置弹性滑移支座时,以及本文提出的在中板边缘及底层中柱设置隔震支座时的地震反应特性,建立了土-地下结构非线性静动力耦合相互作用的二维有限元分析模型,对比分析了采用不同隔震形式对车站主体结构静动力反应特性的影响规律。结果表明:与传统车站结构相比,在中柱顶部设置弹性滑移支座能有效降低车站中柱处的地震损伤,具有更好的抗震性能。采用本文提出的中板边缘及底层中柱设置隔震支座,可以在减小中柱所受地震损伤的同时,有效地保证结构中板在强地震中不受严重损伤,从而提高车站的整体抗震性能。

In view of the weak seismic components of subway underground station structure,the seismic response characteristics of the traditional station structure,the station structure with the elastic sliding bearing setting at the top of the middle columns on the top and ground floor,and the proposed station structure with the elastic sliding bearing setting at the edge of the middle plate and the middle columns on the ground floor are studied.A 2D global time-domain finite element analysis model is built for the nonlinear statically and dynamically coupled soil-main structure interaction.The influence rules of the interlayer displacement,angle,seismic damage and dynamic force response of the main structure of the station are compared and analyzed when different isolating systems are adopted.The results show that,compared with the traditional station structure,the station structure with the elastic sliding bearing setting at the top of the middle columns suffers less damage in earthquake and has better seismic performance.The station structure with the elastic sliding bearing setting at the edge of the middle plate and the middle columns on the ground floor proposed in this paper can ensure that the middle columns of the station structure are not severely damaged and can be replaced quickly after the earthquake,which can improve the overall seismic performance of the subway station structure and the rapid recovery ability of the structural function after the earthquake.