Abstract: To study the influence of compression deformation of the insulation layer under long-term aircraft loading on the temperature field of permafrost runway foundation (hereinafter referred to as subgrade), and in combination with the runway structure of Qinghai -Tibet Plateau airports, the finite element method was used to analyze the maximum stress range at the insulation layer during taxing of eight different types of aircraft. Furthermore, based on indoor model tests, the influence rule of the compression ratio of extruded polystyrene (XPS) insulation boardon its thermal conductivity under this stress, as well as the thermal insulation performance of XPS insulation boards with different thicknesses, was investigated. On this basis, a computational model of airport permafrostsubgrade was established for XPS insulation boards of different thicknesses. The effects of different compressionratios of the insulation layer on the thaw depth of permafrost subgrade and of runway width on the degradation of thermal insulation performance of XPS insulation boards were comparatively analyzed. The results show that the placement of XPS insulation boards can significantly reduce the thaw depth of the subgrade, and at the same compression ratio of the insulation board, an increase in runway width leads to an increase in the thaw depth of the subgrade. This study can provide a reference basis for the design of airfield pavements in permafrost regions of China.

Key words: XPS insulation board;permafrost, runway foundation, temperature field, compressibility