Coupled Thermo-Hydro-Mechanical Analysis of Freeze-Thaw Behavior of Pavement Structure over a Box Culvert

Evaluation of frost heave is essential for good design of a geotechnical structure in cold regions. Frost heave often causes severe roughness and cracking of structures like pavements. To model frost heave around a box culvert, a practical coupled thermo-hydro-mechanical (THM) model is presented. The performance of the proposed THM model, which can predict the freeze-thaw behavior of unsaturated soil, is demonstrated through frost heave tests under different conditions. A pavement structure located above a box culvert was simulated, and the analysis could reproduce phenomena observed in the field, including uneven upheave of the pavement and frost-heaving force induced by frost-susceptible backfill. To mitigate such damages, the mechanism and countermeasure of uneven frost heave were investigated. It was revealed that the freeze-thaw action considerably affects smoothness and failure of the pavement structure. In addition, the use of insulation may reduce roughness and extend the fatigue life of the pavement structure. The findings of this study are useful for minimizing frost heave in geotechnical structures.