Acoustic–vibration characteristics and low–structural–noise optimization design of upright sound barrier for rail transit

Noise is a major problem in the development of rapid rail transit systems. To reduce the impact of wheel – rail noise and other types of noise on the sound environment along the railway, sound barriers are often installed on both sides of the rail transit system, the main purpose of which is to prevent the propagation of noise. Therefore, sound barriers are the most important noise reduction measure for rail transit. However, when a train passes, the sound barrier vibrates and produces noise because of the vibration energy transmission caused by the running vehicle. If the noise generated by the sound barrier influences the secondary structural noise in the railway environment, the noise reduction effect and the function of the sound barrier will be weakened. Based on the train – track – bridge interaction theory, a coupling dynamic vehicle – track – bridge – sound barrier model was established to systematically study the vibration characteristics of the upright sound barrier (USB), and the acoustic radiation characteristics of the sound barrier were analysed in combination with the acoustic boundary element theory. On this basis, low – noise optimization design schemes of the USB were developed for high – speed railway (HSR) and urban rail transit (URT). The results showed that the stiffened plate design of the USB had a good effect on vibration and noise reduction.