Full-Band Track Irregularity Spectrum Considering the Longitudinal Distribution of Rail Corrugation Shape and Random Vibration Responses of Floating Slab Track System

The floating slab track (FST) system is a type of railway structure with good vibration reduction effects, widely used in urban rail transit lines around the world. The corrugation of rails has an important impact on the high-frequency vibration and noise of the wheel–rail system, and is closely related to the vibration reduction effect of the FST. First, the longitudinal distribution characteristics of the rail corrugation shape based on on-site measured data are considered, and a new model of rail corrugation roughness is established. Second, based on the track geometry irregularity spectrum and Sato’s roughness spectrum, a full-band track irregularity spectrum considering the longitudinal distribution of rail corrugation shape is established. Then, a vehicle–track–tunnel coupled dynamics model is established, and the virtual excitation method is used to solve the random vibration response of the full-band FST and tunnel coupling system under track irregularity excitation, and the accuracy of the coupling model is verified through the results compared by finite element method and on-site experiments. Finally, the influence of rail corrugation on the random vibration response of the track system is studied and analyzed. It was found that when the excitation frequency of rail corrugation is coupled with the main frequency of excitation, the vibration response of the FST is significantly increased.