Transverse thermal difference of high-speed railway roadbed in seasonally frozen regions

Transverse thermal regime differences are widespread for high-speed railway (HSR) roadbed in seasonally frozen regions. On the basis of the monitored data of four typical roadbed sections from Harbin–Dalian HSR in seasonally frozen regions of China, the external influence and heat absorption of different parts of the roadbed are studied quantitatively through the comparison of the temperature amplitude and average temperature; the characteristics of the frost penetration development are also analysed. The variations in temperature during the coldest and hottest months with depth are analysed as well. On the basis of these analyses, the influence factors and potential hazards of the transverse differences are discussed. It is stated that the west shoulders are most influenced by the external environment. The temperature in the coldest and warmest months at a certain depth is characterised by a spindle shape intersection. The increase in the latitude and roadbed height may aggravate the transverse thermal regime difference. In addition, the roadbed transverse thermal difference may induce uneven roadbed deformation; hence, the roadbed stability and the ride comfort of the track structure may be threatened. Therefore, further relevant monitoring and deformation mechanics studies should be conducted.