Seismic response analysis of rectangular prefabricated subway station structure

The development and application of prefabricated assembly technology has become an important measure to achieve industrial optimization and upgrading and sustainable development of construction engineering. The application of prefabricated assembly technology in underground engineering is in its infancy, and the seismic research on prefabricated underground structures is scarce. Therefore, this paper establishes refined finite element models (FEMs) of prefabricated and cast-in-place underground structures based on an actual project of a subway station. The developed FEMs are used to conduct a series of seismic time-history analyses considering soil-structure interaction to compare the responses of a prefabricated underground structure with rigid splicing joints or non-rigid splicing joints with that of a cast-in-place underground structure of the same structural form. In addition, the influence of the splicing properties of different parts on the inter-story displacement and internal forces of the prefabricated underground structure are systematically investigated. Tt was found that the inter -story displacement and component deformation for prefabricated underground structures with rigid joints are basically the same as those of the cast-in-place underground structure; however, both the internal force and damage at the bottom of center column decrease slightly. On the other hand, prefabricated underground structures with non-rigid splicing joints experience a slight increase (less than5%) in inter-story displacement, but more obvious mid-span deflection of the laminated slab. However, the internal force response and damage degree of their center column are significantly reduced compared to cast-in-place structures. It was also revealed that the bonding strength of new-old concrete interface of the horizontal laminated components is the main factor that reduces the lateral stiffness and causes redistribution of the prefabricated underground structures' internal forces.