可液化场地中复杂异跨地铁地下车站结构的地震反应分析

地基液化是导致地铁地下车站结构在地震中发生严重破坏的重要威胁之一,然而目前对可液化场地中地铁地下车站结构地震反应的研究较少,尤其是针对大型复杂异跨地铁地下车站结构地震反应的研究更是少见。通过引入砂土液化大变形本构模型,采用有限元网格自适应调整技术克服土体网格大变形的畸变问题,建立了可液化场地土一复杂异跨地铁车站结构静动耦合非线性相互作用的有限元数值模型,分析了该相互作用体系的场地液化分布特征、异跨车站结构上浮特征、周围场地位移沉降及矢量特征、结构侧向变形和地震损伤破坏特征等,初步揭示了该相互作用体系的地震反应规律及液化地基中大型异跨地下结构的地震破坏特征,研究成果可为提高可液化场地中异跨地铁车站结构地震反应的认识及完善其抗震设计方法提供合理的参考。

Seismic response analysis of complex subway station structure with unequal-span in liquefiable foundation

Foundation liquefaction is one of the important causes for serious damage of subway underground station structure in earthquake. However,there is a little research on the seismic response of subway underground station structure in liquefiable sites at present. The research on the seismic response of large and complex underground station structures with unequal spans is even more rare. In this paper, by introducing the large deformation constitutive model of sand liquefaction and using the finite element mesh adaptive adjustment technique to overcome the distortion of soil mesh large deformation, a finite element numerical model of static and dynamic coupling nonlinear interaction between liquefied site soil and complex unequal span subway station structure was established. The distribution characteristics of site liquefaction, floating characteristics of unequal-span station structure, displacement settlement and vector characteristics of surrounding site, lateral deformation and seismic damage characteristics of the interaction system were analyzed. The seismic response law of the interaction system and the seismic failure characteristics of large-scale unequal-span underground structures in liquefied foundation were preliminarily revealed. The research results help to improve the understanding of the seismic response of unequal-span subway station structures in liquefied sites and the seismic design methods.