Influence analysis on the effect of rail fastening parameters on the vibration response of track–bridge system

Abstract

With the prevalent application of the box girders in the express railway and urban rail transit systems, problems such as vibrations and noises of bridge structures caused by passing vehicles have increasingly aroused concerns than before, and thus, consequently damping fasteners are widely integrated into the design of track structures. In accordance with the vibration theory of slab track–box girder structures, and with reference to the change in types and parameters of damping fasteners, the article focuses on the probe into the effects of four common types of damping fasteners on the vibrations of box girders, by setting up the analytical model of spatial entity of track-slab–cement and asphalt mortar–concrete base layer–box girder coupled system and taking the velocity admittance of box girder as an evaluating index. The purpose of the study is to offer some feasible suggestions on a more scientific engineering designing in reducing the vibrations and noises. The calculating results show that (1) the stiffness of fastenings has distinct effects on the reduction in bridge vibration at 100 Hz and above, with Cologne egg rail fastening system as the best; but damping fastenings will stimulate stronger vibrations on rails in return. (2) The increase in damping on fastening system is not obvious to the reduction in bridge vibration, but in favor of vibration of rails above 60 Hz. (3) Within a certain frequency range, an anti-resonance phenomenon may emerge in the fastening system, which will undermine the damping effects or even reversely lead to an increase in structure vibration.