Effect Of Dynamic Load And Cooling Path On The Frost Characteristics Of Saturated Lean Clay

With the traffic load increase in heavy-haul railways, the subgrade's frost heave damage should be emphasized in colder seasons for operational safety. The effects of dynamic vehicle load (mean value and frequency), step cooling path, and dry density on filler's frost characteristics are not explored in existing heavy-haul lines. This study performed L-9(4(3)) orthogonal tests for saturated lean clay filler. The test results were analyzed using the analysis of variance method and the grey incidence (GI) model. The external water supply caused a shallower frozen depth, more segregated ice, and a frost heave ratio exceeding 4.0% under a dynamic load. The dry density, associated with the migrating water's permeability, had the highest significance on the open system's frost heave. As the phase change of water depends on the negative temperature, the step cooling path had the highest impact on the frost heave ratio and frozen depth in the closed system. The significance of dynamic load on the frost heave ratio was slight, so an increase in axle load and operating speed had little impact on the lean clay's frost heave characteristics. Compared with other factors, the water supply conditions had the most significant impact on the test results. This study clarifies the significance of the four factors on the filler's frost characteristics in heavy-haul railways, which serves as an essential guide to frost damage management.