异跨框架式地铁地下车站结构抗震性能水平与评价方法研究

Performance levels and evaluation method for seismic behaviors of a large-scale underground subway station with unequal-span frame

针对现有异跨地铁地下车站结构抗震分析方法缺乏合理性能评价指标的问题。考虑土体与结构混凝土的材料非线性和接触非线性,建立了土-异跨地铁车站静动耦合整体时域有限元数值模型,通过在基岩处输入不同强度等级和类型的地震动,研究了异跨地铁车站结构的侧向变形规律与地震损伤特性,揭示了该车站结构的地震损伤破坏演化过程,建立了基于层间位移角与损伤破坏状态的异跨框架式地下车站结构抗震性能水平评价方法与物理特征描述。所建议的抗震性能评价方法能初步应用于异跨框架式地下结构的抗震性能水平分析。

The existing seismic analysis methods and performance evaluation indicators of large-scale underground subway stations with unequal-span frame are insufficient at present. The nonlinear static and dynamic coupled time domain finite element model was established to simulate the earthquake response among the soil and the complicated underground structure by considering the dynamic contact interaction of the interfaces and the nonlinear properties of soils and concrete under dynamic loading. Based on the modelling, the lateral deformation characteristics, seismic damage levels and failure mechanism of the unequal-span underground frame subway station were revealed by inputting different intensities and types of ground motion at the bedrock. In addition, the seismic performance evaluation method and physical characteristics of the unequal-span frame type underground station structures based on the inter-layer displacement angle and damage state were proposed. The seismic performance evaluation method developed in this paper can be preliminaryly applied to the seismic performance level analysis of such unequal-span frame underground structures.