Vibration Response Characteristics and Noise Analysis of Metro Transition Section Structure

To study the response characteristics of metro vibration in the transition section, the vibration and noise are tested in the track area of the transition section in front of the station and the adjacent ground of Guangzhou Kengkou station. By conducting Fourier transform on the obtained vibration acceleration, the transverse propagation law of train vibration and the influencing factors of train vibration are analyzed. The following conclusions are obtained: train braking behavior, rail joint and increase of train load will enhance the train vibration, while gravel track bed can effectively reduce the train vibration propagation; when the train is passing through the upper and lower lines, the peak vibration acceleration of the sleeper measuring point is 10.80 and 4.22 m/s2 respectively, the ground vibration acceleration peak value being 0.07 m/s2, and the lateral propagation of the vibration acceleration presents a gradual attenuation trend. The maximum frequency response of the lower sleeper caused by train vibration is about 110 Hz, the frequency response range is mainly 0~400 Hz; the maximum frequency response of the side track sleeper is about 80 Hz, the frequency response range is 0~200 Hz; the maximum frequency response on the ground is about 50 Hz, the frequeucy range is 0~100 Hz. The high frequency component of the whole train induced vibration propagation process is greatly attenuated, and the low frequency response is enlarged when it reaches the ground. The maximum noise value of the vibration noise on the side near the track is 95.5 dB, and the maximum value of the noise at the bottom of the building far away from the track is 87.9 dB, exceeding the specified noise limitation 75 dB. The vibration noise has a small amplitude attenuation in the transverse direction.