Innovative Measures for Reducing Noise Radiation from Steel Railway Bridges

Reconstruction of low-frequency bridge noise using an inverse modal acoustic transfer vector method

“…Train-induced vibration and structure-borne noise radiating from the bridge can be treated as a steady process during the train's passage, and bridge noise can be calculated in the frequency domain. 26,27 An acoustic transfer vector (ATV)-based method can be used to predict bridge noise, as follows 28 P b ðxÞ ¼ATVðxÞ T V b ðxÞ (1) where P b ðxÞ is the sound pressure spectra emitted from the bridge; ATVðxÞ is the transfer function between the sound pressure at selected field points and the surface velocity with a unit normal velocity applied on the element surface; V b ðxÞ is the surface velocity vector; T is the matrix transpose operation and x is the angular frequency vector. The ATVs can be easily obtained using BEM, and the SPLs of the structure can be directly measured.…”

“…The overall noise level of a railway bridge system is usually larger than that of the ground track system, due to train-induced bridge vibration. Stiebel et al 1 showed that the total noise levels of railway steel bridges with directly fastened track, steel bridges with ballasted track and concrete bridges with ballasted track could be 12 dB, 6 dB or 3 dB greater than plain track, respectively. Experimental and numerical results showed that concrete viaducts mainly generated low-frequency noise emissions Hz), 2 which were easy to ignore when A-weighted sound pressure level (SPL) was utilised for evaluation.…”

The acoustic specificity of steel-railway bridges

“…The threat to the environment may be steel objects built several or dozens of years ago, but also modern ones, designed in recent years [6,8,10]. Bridges made of prestressed concrete or composite steel and concrete generally cause much less acoustic problems, but such problems cannot be excluded [5,7].…”