Study on the influence of resilient wheels on vibration and acoustic radiation characteristics of suburban railway concrete box girder bridges

Abstract

To control noise radiated from suburban railway concrete box girder bridges, damping and vibration isolation measures are normally applied. However, it is often the case that applying such measures to a single or few spans is not adequate, and the incurred cost is too high if more spans are subsequently treated. Alternative solutions must be sought. Therefore, in this paper a study is performed on the influence of resilient wheels on vibration and acoustic radiation characteristics of suburban railway concrete box girder bridges, providing a reference from the noise aspect to the applicability of resilient wheels to suburban railways. The study is carried out by representing bridge vibration using the finite element method and calculating the wheel-rail forces in the frequency domain. Sound radiation from the bridge is predicted using the boundary element method. The simulation model is validated by in-situ measured results. The model is then used to analyse the influence of resilient wheel structure and rubber parameters on bridge structure noise, from which the following conclusions can be drawn: (1) The influence of resilient wheel on bridge noise is related to the vertical decoupling frequency of resilient wheel. The lower the decoupling frequency is, the lower the bridge noise is; (2) Different types of resilient wheels have different decoupling frequencies, among which shear type and press-shear type have the lowest vertical decoupling frequency and the best noise reduction effect; (3) The total sound pressure level of box girder structure noise radiation will be reduced by using resilient wheels, which is related to the Young's modulus of rubber. The higher Young's modulus is, the higher the bridge noise is, however, when the Young's modulus exceeds 200 MPa, the impact of the Young's modulus on the bridge noise is considerably small; (4) Under the commonly used roughness spectrum, the coefficient of change of bridge noise with speed under the action of resilient wheels is greater than that of the steel wheel. With the increase of speed, the noise reduction effect of bridge noise by resilient wheels decreases, but the choice of roughness spectrum does not affect the evaluation of noise reduction effect of bridge noise by resilient wheels.