Noise and Vibration Control of the South Railway Bridge of Budapest

The paper reports on the noise and vibration control of a 451 m long steel railway bridge. The vibration and noise generation mechanisms were investigated first. Vibration of the rail fixture, sleeper, horizontal and main girders and the steel walking plates were measured, together with noise measurements in a number of measuring points both in the close vicinity of the bridge and at larger distances. The obtained vibration characteristics were compared to results of numerical calculations, enabling the identification of vibration propagation mechanisms. The noise radiation of the investigated bridge section was investigated by means of a combined experimental numerical method. Eventually, both the horizontal steel walking plates and the main vertical girders were identified as major noise radiators. Based on the investigations a combined noise control package, including the vibration isolation system CDM ISOFERPONT and replacement of the steel walking plates by a composite plate structure, was developed and realized. The final measurements have shown that the average vibration and noise levels were reduced by 5 to 8 dB. .