# Influence of Uneven Subgrade Frost Heave on Deformation and Damage of CRTSIII Slab Track
## 4 Results and Discussion
### Influence of the Subgrade Frost Heaving Geometric Parameters
#### 4.3.1 Influence on Track Structure Deformation and Interlayer Seam  
Table 3 shows the vertical displacements of the rail, slab, and base under different frost heaving wavelengths and wave amplitudes when the frost heaving wave peak acted on (e). The observations show that the displacement of the track structure shifted from bottom to top. The displacement from the base to the rail gradually reduced. The structural  
Figure 16: Average damage factor of the track structure at different frost heaving positions.  
Figure 15: Damage diagram of the track structure: (a) Slab damage; (b) concrete base damage.  
displacement of each layer increased with an increase in frost heaving wavelength and wave amplitude. The displacement was mainly dominated by frost heave wave amplitude.  
Figure 18a,b, respectively, show the self-compacting base interlayer seam and the base subgrade surface interlayer seam when frost heaving wave peak acted on (e). It can be seen that the variation in the two interlayer seams was consistent, which decreased with  
Figure 17: Frost heaving condition.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Vertical Displacement of Rail (mm)**} \\ \hline \(A\)/mm & \multicolumn{2}{c}{**\(\lambda\)/m**} & \multicolumn{1}{c}{**5**} & **10** & **15** & **20** & **25** & **30** \\ \hline
5 & 3.72 & 4.22 & 4.51 & 4.62 & 4.67 & 4.70 \\ \hline
10 & 8.11 & 8.93 & 9.31 & 9.50 & 9.59 & 9.64 \\ \hline
15 & 12.77 & 13.76 & 14.12 & 14.40 & 14.52 & 14.59 \\ \hline
20 & 17.57 & 18.61 & 19.04 & 19.31 & 19.46 & 19.54 \\ \hline
25 & 22.36 & 23.48 & 24.04 & 24.22 & 24.41 & 24.50 \\ \hline
30 & 27.26 & 27.56 & 28.94 & 29.15 & 29.36 & 29.48 \\ \hline \multicolumn{6}{c}{**Vertical Displacement of Composite slab (mm)**} \\ \hline \(A\)/mm & \multicolumn{2}{c}{**\(\lambda\)/m**} & \multicolumn{1}{c}{**5**} & **10** & **15** & **20** & **25** & **30** \\ \hline
5 & 3.77 & 4.29 & 4.57 & 4.68 & 4.72 & 4.75 \\ \hline
10 & 8.36 & 9.02 & 9.36 & 9.57 & 9.65 & 9.70 \\ \hline
15 & 13.03 & 13.95 & 14.19 & 14.46 & 14.59 & 14.65 \\ \hline
20 &an increase in frost heaving wavelength and increased with an increase in frost heaving wave amplitude. When the frost heaving wavelength was 5 or 10 m, an increase in frost heaving wave amplitude resulted in a significant increase in the interlayer seam. The maximum seam between the self-compacting concrete and the base was 21.84 mm, and the maximum seam between the base and subgrade surface was 25.43 mm. When the frost heaving wavelength exceeded 15 m, the peak values of the two were only 3.39 and 4.98 mm, respectively. It can be seen that the frost heaving wavelength had a greater influence on the interlayer seam, and the interlayer seam was more sensitive to the frost heaving with a wavelength less than 10 m. This is because the critical wavelength of the track structure was calculated as 10.99 m, according to the literature [35]. When the frost heaving wavelength was less than the critical wavelength, the interlayer seam changed obviously; when the frost heaving wavelength was larger than the critical wavelength, the frost heaving wavelength had little effect on the seam between layers. In addition, it can be seen from the difference between the two seams, as shown in Figure 19, that when the wavelength was small, the stiffness difference between the base and the subgrade surface was amplified, resulting in the seam between the base and the subgrade surface which was higher than that between the self-compacting concrete and the base. When the wavelength was high, the deformation between the base and the subgrade surface was relatively uniform, while the composite slab was a unit slab and there was no constraint at both ends. This resulted in a relatively larger interlayer seam between the self-compacting concrete and the base.