可液化土层对地下结构地震反应的影响研究

为了研究砂土液化大变形对地铁车站结构产生的重要影响,使用FLAC~(3D),采用PL-Fin土体液化本构模型,总结地下结构位于可液化土层时,液化土层从液化初始到产生液化大变形时刻,土体液化、结构位移变形和结构周围土体应力与结构应力变化规律,并与非液化场地下的地下结构地震反应进行对比。主要结论有:地铁车站结构从底部开始液化,引起两侧土体的移动和结构的倾斜上浮;由于结构两侧土体液化较轻微,结构左侧墙临近土体应力及结构应力在液化和非液化场地中的变化规律比较类似,底部土体液化较严重导致液化地层中结构底板及底板相邻土体应力变化同非液化土层存在较大差异。

Research on Influence of Liquefiable Soil on Seismic Response of Underground Structure

In order to study the significant influence of large deformation induced by sand on the metro station structure,the conditions where an underground structure is located in a liquefiable soil layer and a non-liquefied soil layer are considered and compared based on the PL-Fin constitutive model developed by FLAC~(3D). The liquefied state,displacement and deformation of the structure and the stress of the structural and surrounding soils in the case of large deformation are analyzed and compared. The main conclusions are that the soil at the bottom of the structure is most easily liquefied,which results in movement of the soil on both sides of the structure and in incline and rise of the structure. The stress of the structural and surrounding soils on the leftside of the structure in liquefied soil is similar to that of non-liquefied soil in the slightly liquefied state,but it is much different from the soil at the bottom of the structure in a severely liquefied state.