Prediction of train-induced vibration in a large-scale underground rail transit hub based on transfer function formulation

This study investigates a major underground rail transit hub and predicts structural vibrations induced by high-speed railway and metro train operations using the transfer function method. The results are compared with conventional finite element calculations to assess the applicability of the proposed approach for complex large-scale underground structures. The results demonstrate that: (1) the transfer function method provides an effective and accurate approach for predicting train-induced vibrations in complex structures, demonstrating good agreement with conventional numerical simulations over the 10-100 Hz frequency range, with an average mean squared error (MSE) of 5.475 dB 2 and an average coefficient of determination (R 2 ) of 0.9194;(2) compared with traditional finite element methods, the proposed approach exhibits significantly higher computational efficiency, making it particularly suitable for analyzing multiple train–track parameter scenarios in large-scale structures; (3) train-induced underground vibrations exhibit amplification zones on both sides of the track, which are associated with the dynamic wave propagation characteristics of the coupled tunnel–soil–structure system. Peak responses induced by high-speed trains are concentrated in the 40–60 Hz frequency range, whereas metro trains primarily generate peak responses in the 50-80 Hz range, reflecting differences in train–track dynamic interactions; (4) within the investigated parameter ranges, train speed significantly influences structural vibration, reducing fastener stiffness suppresses high-frequency vibration, and increasing damping mitigates responses in the 50-80 Hz band. These findings provide theoretical support for vibration prediction and mitigation in underground rail transit hubs and offer useful guidance for vibration serviceability assessment and low-frequency noise control of structures adjacent to high-speed railway and metro lines.