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

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.