Investigating the Effect of Ice Formation and Thawing on Permanent Deformation of Railroad Ballast through Large-Scale Triaxial Cyclic Testing

In seasonally cold regions, railroad tracks are subjected to ice formation and thawing due to significant seasonal temperature fluctuations, posing challenges for the maintenance of ballasted railway tracks. Because little attention has been given to the impact of ice formation and thawing on the permanent deformation of railroad ballast, this study investigates the impact through large-scale triaxial cyclic testing, utilizing a newly developed freezing system to simulate frozen conditions. The results demonstrate that, in comparison to dry and thawed states, frozen ballast subjected to progressive thawing exhibits the most substantial permanent deformation under the same loading cycles. The rate of permanent deformation in frozen ballast exhibits a consistent pattern in relation to the decreasing rate of ice content. These findings provide valuable insights into the effect of ice formation and thawing on the permanent deformation of ballast and similar large aggregate structures.