AN INVESTIGATION OF NOISE FROM TRAINS ON BRIDGES

Abstract

The introduction of new railway systems in urban areas to ease road traffic congestion has led to concerns about the noise from trains, particularly as tracks often pass close to residential dwellings. One specific issue relates to the noise from trains or trams on bridges. The bridge design and construction can increase noise levels above those when the track is at grade. This paper addresses this issue, and reports two case studies to quantify the contributions to the total noise level from the wheel/rail noise, and from the noise radiated by the bridge structure itself including both the deck and the parapets. The studies involved, in the first case, consideration of the design and construction of a concrete and steel bridge and a comparison of pre-construction predictions, supported by finite element analysis, with in-use noise measurements. The second case involved noise and vibration measurements on an existing bridge to quantify the noise from the different sources, to compare simple predictions with measured noise levels, and to evaluate the effectiveness of various noise control measures. The good agreement between the predicted and measured levels in both case studies has led to the conclusion that the techniques provides a cost-effective method for the prediction of noise levels with an acceptable degree of accuracy. The techniques can also be used to evaluate the benefits to be gained from alternative noise and vibration control measures, and thus to define the most cost-effective control measure prior to implementation.