强震作用下地铁车站结构损伤破坏的三维非线性动力分析

3D Nonlinear Damage Analysis of Metro-station Structures Under Strong Seismic Loading

为了研究地铁车站结构在强震作用下的动力响应及破坏机理,基于混凝土损伤塑性模型、岩土扩展的Drucker-Prager模型、土-结构相互作用以及人工边界等相关理论,利用ABAQUS软件建立了强震作用下地铁车站的动态响应与损伤破坏的二维、三维精细化非线性有限元分析模型,并对柱端设置隔震器的地铁车站结构进行了三维非线性动力分析.分析结果表明:所建立的有限元分析模型能较好地反映强震荷载作用下钢筋混凝土结构的动力特性以及土-地下结构之间相互作用,适用于地下结构抗震分析;三维有限元模型的分析结果比二维有限元模型的分析结果更为准确地反映强震作用下地下结构的破坏特性,并与现场观测的破坏形态具有较好的一致性;碟形弹簧和铅芯橡胶构成的三维隔震支座具有较大的竖向刚度和抵抗侧向变形能力,在地铁车站中柱端部设置隔震支座可以大幅减小中柱的变形及损伤破坏程度.

In order to investigate the dynamic response and the failure mechanism of metro-station structures under strong seismic loading,a two-dimensional（2D） and a three-dimensional（3D） nonlinear finite element models of the Daikai subway station during Kobe earthquake were established based on damaged plasticity model for concrete,extended Drucker-Prager model for soil,soil-underground structure interaction theory and artificial boundary theory.The 3D nonlinear responses of the Daikai subway station with isolators fixed at the column ends subjected to seismic loading were also analyzed.The results show that：（1） the finite element models established in this paper can describe the dynamic properties of the reinforced concrete structure and the dynamic interaction of soil-underground structure properly;（2） the 3D numerical results agree well with the in situ observations by comparison of the numerical results of the 2D and 3D models,and the failure mode of the column in the metro-station structure under seismic loading can not be predicted precisely by the 2D analysis;（3） the 3D shock isolator,composed of dish spring and lead rubber beading,has a rather large vertical stiffness and good resistance to lateral deformation,and consequently can markedly reduce the deformation and damage of the column when fixed at the ends of the column.