Seismic responses of an intensively constructed metro station-passageway-shaft structure system

Intensive construction methods offer benefits for metro station development,yet they present challenges for seismic design due to the spatially asymmetric configuration of passageway-shaft structures.In this study,a detailed numerical model of a station-passageway-shaft structure system built using intensive construction methods was developed and the deformation and damage modes under seismic loadings were analyzed.The results indicate that inconsistent deformation between the shaft and the station generates interaction through the connecting passageway,leading to damage near the opening of the station structure and both ends of the connecting passageway Damage is more severe under longitudinal excitation.Compared with the opening plan that spans four segments,the opening plan that spans five segments exacerbates the overall degree of damage to the structure system.Under transverse excitation,the presence of interior structures intensifies the damage to the station and connecting passageway,while with such internal structure in place the impact is relatively minor under longitudinal excitation.Reinforcement with steel segments near the station opening can appreciably attenuate the damage.In contrast,introducing flexible joints at both ends of the connecting passageway intensifies the damage.Hence,reinforcement using steel segments emerges as an optimal seismic mitigation strategy.