Statistical energy method for noise reduction performance of the vertical noise barrier alongside railway bridges

With the aim of studying the noise reduction performance of the vertical noise barrier on railway bridges, this paper introduces the statistical energy analysis (SEA) to predict their insertion losses. Two sub-models were built to estimate the transmission losses (TLs) between the two subsystems, thus the isolation properties and the sound absorption were simulated. A field measurement targeting the noise distribution on the transverse plane at the mid-span of the bridge was conducted, and the developed SEA model of the barrier was verified to be accurate. On this basis, the height, structural style, material composition and sound leakage of the barrier were selected as the objects for parametric analysis. The results show that the insertion losses decrease with the increasing horizontal distance, from 12 dB(A) to 11 dB(A) at points 7.5 m and 15 m away from the central line of the rail track. The most efficient enhancement on the performance can be obtained by heightening the barrier in the range of 3-4 m. Additional insertion losses can be obtained by optimizing structural styles at frequencies above 200 Hz. In addition, noise at the frequency range of 100-1000 Hz can be further controlled by internal sound absorption material. Finally, it is also of great importance to reduce sound leakage of the barrier plate. (C) 2020 Elsevier Ltd. All rights reserved.