Numerical Simulation For Temperature Field Of Roadbed On Permafrost With Insulation

Roadbed construction on permafrost will give substantial disturb for the heat and mass transfer balance between the ground surface and atmosphere, usually, roadbed construction increases the amount of absorbed heat via vegetation removal, solar radiation and increased role of water activities in the adjoining area, then cause the local degradation of the permafrost underneath, as a result may lead to damage of the roadbed. In this paper, the method of 2-D finite element analysis was conducted to simulate the thermal state of the roadbed with insulations on permafrost. To check the efficiency of the insulations, by varying the thickness, the width and the position of the insulations (expandable polystyrene insulation layer (EPS); Polyurethane(PU)) and the material of the roadbed surface in the calculation, the maximum thawed depths during the following 50 years on permafrost under the roadbed were simulated. By comparing and analysing the computed results and the change of the raised permafrost table, a conclusion is gived that the roadbed with insulations on the permafrost protects the permafrost well under itself, and the rational position and thickness for insulation were suggested.