Effect of Using Geosynthetics in Mitigation of Freeze-Thaw through Numerical Analysis

Pavement deterioration due to frost action is a challenge for transportation infrastructure in the northern part of United States. Combination of the variation of subgrade temperature, moisture, and soil type leads from minor to severe frost damage. Accumulated water causes the differential frost heave during freezing temperature followed by settlement in subsequent thawing days in seasonally frozen areas. While the classical solution suggests using granular materials up to freezing depth which comes with substantial cost, insulation can be an effective alternative to prevent the frost action reaching the frost susceptible soil. With an attempt to moisture and temperature adjustment, geocomposite insulation layer was modeled in numerical environment. Geosynthetics layers consisting a geonet sandwiched between geotextiles at top and bottom was placed before the subgrade. The top and bottom geotextile layers acted to prevent both downward and upward moisture flow in the pavement. The numerical modeling results yielded to less moisture variation following precipitation. In addition, it was also found that the maximum freezing depth was reduced after using the geosynthetics layer. As such, the study suggests insulation using geosynthetics layer can be an effective solution for reducing frost damage risk in frost susceptible areas.