Objective To solve the vibration noise issues caused by different station upper-cover structures under metro operation, it is necessary to explore the dynamic response differences between the representative vertically stacked and fully integrated types of metro station upper-cover structures.
Method Combining a specific engineering case study, an overall numerical model of soil layer-track-station-upper-cover structure is established. An artificial excitation numerically defined excitation force function simulating metro train loads in China is determined through empirical analysis. The rationality of the model and its parameter selection are validated through a comparison between the numerical simulation results and the measured data from the center of the station's track slab and the sidewall of the track area. Through numerical simulation, the dynamic response of the two types of station upper-cover structures are analyzed from time domain, frequency domain, and maximum Z-vibration level three aspects, when the train runs at 60 km/h, 80 km/h, and 100 km/h respectively.
Result & Conclusion The peak acceleration and maximum Z-vibration level at each floor in both types of station upper-cover structures increase with the increase of train speed, showing a trend of decreasing and then increasing as the floor height increases. The vibration frequency distribution range at the center of the second floor slab in both types of station upper-cover structures gradually approaches the lower frequency region with the decrease of train speed. Under the same train running speed, the peak acceleration, spectral peak amplitude, and maximum Z-vibration level of each floor in the fully integrated upper-cover structures are all greater than those of the vertically stacked type.
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