Experimental Study on Frost Heaving of Soils under Unidirectional Freezing Considering Varying Percent Fines and Moisture Content

Frost heaving is a significant geotechnical concern in cold regions, where subgrade soil is exposed to freezing temperatures. This phenomenon arises when water migrates to the freezing zone within the soil and forms ice lenses, causing volumetric expansion and upward soil displacement. The resulting heave poses serious challenges for infrastructure, affecting roads, pavements, and foundations, and often leading to costly repairs and structural failures. This study investigates the frost-heaving behavior of fine- and coarse-grained subgrade soils through controlled unidirectional freezing experiments, simulating in situ conditions found in frost-prone areas. Based on the preliminary geotechnical laboratory test results, the soil samples were classified for frost susceptibility using established frost susceptibility classification systems. Further, using a specially fabricated insulated mold, unidirectional freezing tests were performed in a controlled setup. Fine-grained soils were tested by changing the moisture content from ۲۰ to ۵۰%, while coarse-grained soils were tested by adding different amounts of fine particles ranging from ۵ to ۲۵%. The frost heave ratio (FHR) was measured over ۴۸ h of freezing. The study found that moisture content of about ۴۵% or more significantly increases frost heave in fine-grained soils. Whereas in coarse-grained soils, the frost-heave ratio rises with fines content up to ۲۰%, beyond which it decreases. The study further recommends that increasing the thickness of pavement layers is an effective measure to mitigate frost heaving in cold climate regions.

Keywords:

Experimental Analysis , Frost heave ratio , Unidirectional freezing , Percent fines , moisture content