Insulated pavement analysis based on a thermo-hydro-mechanical (THM) coupled finite element model

Flexible pavements in cold regions are subjected to severe environmental conditions. Adding an insulating layer into a regular flexible pavement structure can reduce the frost penetration depth and mitigate uneven frost heave. This study used a thermo-hydro-mechanical coupled model to evaluate the pavement responses for pavements insulated with extruded polystyrene (XPS) boards. Model input parameters were calibrated with experimental and simulation data obtained from a large-scale insulated pavement box and Layered Elastic Analysis. Moreover, the potential application of the simulation results for the structure design of insulated pavement was demonstrated. Numerical simulation results validate that the presence of the insulation layer can efficiently reduce the frost penetration depth, whereas might induce loading capacity and drainage issues.