Numerical study on high-frequency effect of rail corrugation on subway-induced environmental vibrations

Rail corrugation is a common phenomenon in railway engineering, but its high-frequency effects on environmental vibrations are neglected in most previous research. Therefore, a hybrid numerical method was proposed in this paper to analyze subway-induced ground vibrations, especially in the high-frequency range caused by rail corrugation. The analysis model composed of a three-dimensional (3D) load generation subsystem and a two-dimensional (2D) wave propagation subsystem was established based on the vehicle-track coupling method and finite element method, and validated by the measured data. Then the high-frequency effects under different tunnel depths and rail fasteners were further studied. The results show that high-frequency vibrations propagate radially from the tunnel wall to the surrounding soil and transmit to the ground by the dominant path under different tunnel depths. The increase of tunnel depths could result in more serious high-frequency effects in the vibration amplification region. When the depth changes from 17 to 29 m, the 250 Hz ground vibration at around 30 m away from the track increases by 5.6 dB. Besides, it was found that in the commonly used range, the reduction of fastener stiffness can effectively eliminate high-frequency ground vibrations, while there is a significant nonlinear relationship between fastener damping and high-frequency vibration. The findings of this paper could provide references for parameter design in subway construction and rail corrugation remediation, and help create better living environments.