Modeling Train-Induced Vibrations of Layered Soils in Seasonally Frozen Regions

Train-induced vibrations in seasonally frozen regions can disrupt residents’ daily lives and potentially cause damage to nearby structures. This study introduces a three-dimensional coupled model of the train–track–embankment system to investigate vibration propagation under varying temperatures and train speeds. The results demonstrate that vibrations above 8 Hz experience a sharp attenuation as temperature decreases, while lower frequencies decay at a slower rate. During early winter, near-track vibrations decrease, but the effect diminishes further in midwinter. The maximum displacement is observed beneath the surface due to wave reflections at the frozen–unfrozen interfaces. Interestingly, an increase in train speed does not necessarily lead to higher vibration levels; under frozen conditions, it may actually reduce them. A temperature-dependent Green’s function is integrated into the coupled model, offering a novel approach for simulating vibration transmission in frozen soils. These findings provide valuable insights into the interaction between freezing depth and train speed, aiding in the development of effective vibration control strategies and safe railway design in cold regions.