Abstract:The harsh natural environment in the seasonally frozen area has had a great impact on the high-standard operation of the high-speed railway, and may even cause permanent damage to the high-speed railway. To explore the influence of frost heave deformation of high-speed railway subgrade in seasonally frozen areas on the dynamic effect of vehicle-track-subgrade coupling system, a frost heave section of Yinxi high-speed railway was taken as the background, combined with the principle of vehicle-track-subgrade system dynamics and analytical methods, a simplified kinetic model was established. Moreover, a typical single-wave cosine frost heave waveform (frost heave wavelength λ =10 m, frost heave peak value f =10 mm) was selected to discuss the dynamic effects of the track system and the vehicle system respectively, and based on this, a reasonable value of the track stiffness was determined. The research results show that under the action of subgrade frost heave deformation, the amplitudes of dynamic pressure, dynamic displacement, and dynamic acceleration of the track components in the track system fluctuate significantly in the low-frequency band (0-200 Hz). The optimal stiffness ratio of the fastener stiffness to the ballast bed stiffness is 0.5, and the reasonable value of the total track stiffness is in the range of 62-87 kN/mm. In the vehicle system, the vehicle wheel load shedding rate and the vertical acceleration of the vehicle body are inversely proportional to the frost heave wavelength λ. They are directly proportional to the frost heave peak value f.