Insertion Loss Value Dependency of the Low Height Noise Barriers Distance From Railway Track

Railway noise can negatively affect both people’s health and the value of their real estate. Various noise mitigation measures can be used on the railways. One of them is a noise barrier. Under certain conditions, low-noise barriers can be used to mitigate noise along the rails. Such barriers are installed closer to the railway track than regular noise barriers, which mitigate the noise generated by the wheel-rail interaction. In some cases, the gauge at which structures at railway tracks can be installed is limited; thus, this research was carried out to determine which parameters of low noise barriers were most effective dependent on the distance of the track. The aim of the research was to determine which parameters the low noise barrier would be effective at a longer distance from the railway track compared to existing practice. A railway track noise simulation (existing situation without a noise barrier and with a 3.5 m height noise barrier located 4.0 m from the railway track) was developed. The insertion loss of noise barriers was carried out using the Computer Aided Noise Abatement (CadnaA) software. Numerical noise level simulation was done at a distance of 7.5 m and 45 m from the axis of the railway tracks and various speeds of rolling stock from 50 to 250 km/h. The noise level and insertion loss were calculated at different heights from the top of the railway track (1.5 m, 3.5 m, and 5.5 m). It was established that the speed of the rolling stock had almost no influence on the insertion loss of the noise barrier. Therefore, all additional barriers were simulated at the same rolling stock speed of 250 km/h.