Three noise mitigation measures for steel railway bridges

Abstract

Based on an equation given by Cremer and Heckl, describing the noise radiation of plates of limited size, a method of predicting the efficiency of noise mitigation measures of ballast-less steel bridges is presented. Whereas in most studies, computationally demanding numerical modeling is used, this paper describes a simplified approach for investigating three ways of reducing the vibration of bridge structures and hence reducing the noise emission of the bridge. These mitigation measures, intended in conjunction with maintenance work (not reconstruction), are designed to reduce the impact of excitation forces arising from the wheel rail contact and moving masses, by increasing the internal losses of the bridge structure and reducing the vibration level by increasing the effective mass of the bridge structure itself. The predicted results are compared to measured data at bridges where these noise mitigation measures were installed. The objective of the method is that it will simplify the process of selecting the best mitigation measure for a specific steel bridge.