Structural design and seismic performance analysis of partially prefabricated subway station structure

In order to improve the seismic performance of underground subway station structures while taking advantage of modular assembly technology, a novel partially prefabricated structure with prefabricated arch top slab is proposed in this paper. The design concept and joint configurations are introduced, and the feasibility of the proposed design scheme is analyzed considering the construction characteristics and seismic deformation modes of underground structures. Numerical models are established for realistic simulation of grouted mortise-tenon joint and dry mortise-tenon joint, and their reliability is validated by comparing the predictions with experimental results. Three-dimensional finite element models of partially prefabricated structure and monolithic structure are established and their seismic responses under three different seismic excitations are compared. The structural plastic strain distribution, interlaminar deformation response, and initial load distribution and internal force variation of key structural components are evaluated considering different earthquake intensities. The results demonstrate that the columns in monolithic structure are severely damaged, and the plastic strain is concentrated at the column ends; while the columns in partially prefabricated structure experience minimal damage and slight plastic strain is uniformly distributed in the structural components. In addition, the partially prefabricated structure exhibits favorable force distribution and interlaminar deformability compared to monolithic structure, which indicates improved seismic performance of the proposed partially prefabricated underground subway station structure.