Vertical Vibration Response of Long-Span Landscape Pedestrian Bridge Based on Pedestrian Gathering Effect

To investigate the vertical vibration response mechanism of large-span landscape pedestrian bridges under the combined effects of wind loads, pedestrian loads, and assembled crowd loads, this study conducted a systematic analysis of the dynamic response of a single-tower single-cable curved suspension pedestrian bridge structure under the coupled excitation of wind and pedestrians. The main research results are as follows: The gathering of pedestrians as an additional mass will shift the vibration energy toward the low frequency. The peak acceleration is related to the step frequency in a non-monotonic manner, with low-frequency step excitations leading to longer durations of uncomfortable structural vibrations compared to high-frequency steps, suggesting that measures combining crowd control and step frequency intervention can be adopted to enhance comfort. The peak acceleration under the combined effects of wind and pedestrians will be lower than the sum of the responses from wind loads or pedestrian loads alone. The impact of the assembled crowd on the vibration response of the pedestrian bridge is related to the dominant frequency of the external excitation.