... and an X-ray micro-computed tomography instrument. The only water supply mechanism to the tested specimen is vapour transfer. The results indicate that considerable frost heave occurs in coarse-grained soil specimens with a zero fines content. The ratio of frost heave to the initial height can reach 13·8...

... tracks differ from those of open-ended ballasted tracks in which rainwater can freely infiltrate downward to the subballast layer and subgrade through the ballast layer. Moreover, groundwater is another potential water supply for ballasted tracks due to the limited height from the groundwater level...