Novel anti-frost subgrade bed structures a high speed railways in deep seasonally frozen ground regions: Experimental and numerical studies. (1st February 2021)

• Record Type: Journal Article
• Authors: Tai, Bowen; Yue, Zurun; Sun, Tiecheng; Qi, Shouchen; Li, Lei; Yang, Zhihao
• Is Part Of: Construction & building materials. Volume 269(2021)
• Publication Date: 2021-02-01
• Subjects: Thermal-mechanical behaviour -- Anti-frost subgrade bed structure -- Filling material -- Deep seasonally frozen ground; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.121266
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Preventative efficacy of original anti-frost subgrade bed structure is evaluated. General change laws of thermal-mechanical behaviors for embankment are revealed. Effect of novel subgrade bed structures in reducing frost depth is investigated. ACP + CSM + IB subgrade bed structure can best reduce frost depth. Abstract: To reduce the threat of frost damage to the speedy and safe operation of high-speed railways (HSRs) in deep seasonally frozen ground regions, it is necessary to study the anti-frost subgrade bed structure to improve the long-term service performance of HSRs. First, the thermal–mechanical behaviour and preventative efficacy of the original anti-frost subgrade bed structure with graded-crushed rock filling materials are studied. Then, the general change laws of the thermal–mechanical behaviours for embankment engineering in deep seasonally frozen ground regions are revealed. Finally, a finite element model is developed to investigate the anti-frost effects of six novel subgrade bed structures with differential filling materials. The results show that 1) the initial freezing time, initial thawing time and freezing rate of the embankment are substantially different from those of the natural ground; 2) the deformation of the embankment is closely related to the filling depth and frost depth of the embankment. Furthermore, the deformation process is closely related to the seasonal air temperature change; 3) the seasonal frozen depth of the embankment can be reduced by changing the heat entering the subgrade bed and the heat diffusion in the embankment body; and 4) an asphalt concrete pavement + cement stabilized macadam + insulation board subgrade bed structure can best reduce the frost depth. This research provides important technical guidance for the design of the anti-frost subgrade bed structure of the HSR subgrade in deep seasonally frozen ground regions.