Computational feasibility of large-scale three-dimensional seismic analysis for a fully prefabricated underground metro station

As the scale and complexity of underground structures continue to increase, seismic dynamic analysis places higher demands on numerical computing capacity. In this study, a seismic time-history analysis framework based on high-performance parallel computing is adopted, and a refined three-dimensional finite element model with more than five million elements is established to assess the feasibility of large-scale three-dimensional seismic analysis for complex underground structures. In addition, the dynamic response characteristics of a fully prefabricated underground metro station under E2-level earthquake excitation are systematically analysed. The displacement and stress responses of the soil-station system exhibit pronounced spatial non-uniformity, with high-response regions mainly distributed in the lower part of the model, along the soil-structure interface, and at structural geometric transitions and connection zones. Statistical results from representative monitoring points indicate that the locations of peak acceleration and peak displacement do not fully coincide. Further analysis shows that Kobe-wave input mainly amplifies the response without changing the dominant system-level response pattern, whereas changes in CHC joint stiffness primarily affect local response levels and the distribution of high-response regions. Taken together, these findings suggest that, with appropriate modelling and solution strategies, large-scale three-dimensional numerical simulations can effectively characterise the system-level dynamic response of fully prefabricated underground metro stations and provide a practical basis for the seismic assessment of complex underground structures.