Frost heave and thaw settlement represent significant challenges for railway roadbeds in seasonal freezing regions. The repeated occurrence of frost heave and thaw settlement can lead to rapid and uneven deformation, impacting the smoothness of track structures and exacerbating environmental vibration. While many scholars have conducted numerical simulations to analyze roadbed frost heave, there remains a need for further investigation into the mechanisms of frost heave within roadbeds and its contribution to environmental vibration. Several unresolved issues persist, including the mechanisms underlying subgrade frost heave and thaw settlement under the combined influence of moisture, temperature, and cyclic train loads. Additionally, understanding the frost heave deformation mechanisms of subgrade soil, identifying sources of subgrade frost heave deformation, and characterizing temperature field distributions within the subgrade and track structures are essential. Moreover, the construction of full-scale freeze–thaw model experimental equipment for high-speed railways, along with related scientific testing, holds both guiding and practical significance for designing anti-frost heave measures, controlling frost heave-related issues, and addressing environmental vibration in cold regions. Furthermore, there is a need to refine current standards concerning subgrade structures, filling requirements, and anti-freezing standards for high-speed railways in areas with seasonal frozen soil. The research and development of such equipment can provide valuable scientific support for the improvement of standards in this regard.