Research on the Distribution Patterns of Train-Induced Vibrations and Vibration Mitigation Measures in Multi-Line Converging Integrated Transportation Hubs

Using the Suzhou East Station integrated transportation hub as a case study, this paper investigates the train-induced vibration responses and their distribution patterns under various operating conditions of high-speed railway lines, intercity lines, and subway lines. The results show that train speed is the dominant factor: the high-speed railway passage controls floor vibrations in most stories, while line distance also plays a role for some floors. No significant amplification is observed under multi-train convergence; the vibration level is similar to that of the most unfavorable single-train condition. Therefore, only the most unfavorable single-train condition needs to be considered. As vibrations propagate upward through the floors, high-frequency vibrations gradually attenuate while low-frequency vibrations are amplified, leading to an overall amplification of vibrations at the top floors of some buildings. The floor vibration response level decreases as the vertical stiffness of the structural member increases. Cantilevered slabs and mid-span areas are vibration-sensitive zones. For station–city integrated transportation hubs with high-speed railways running underneath, track vibration mitigation measures should be prioritized, such as thickening the track slab. Thin side-wall vibration mitigation pads have a poor vibration reduction effect. When diaphragm walls are rigidly connected to the station and buildings, they amplify the building’s vibration response.