Abstract: In order to reveal the distribution law of the temperature stress of the permafrost wide runway under the coupling effect of multifield, the temperature change process of the permafrost during a cold season in a certain region of Northeast China was simulated via indoor experiment and compared with the temperature field model based on the hydro-thermal coupling theory. Furthermore, according to the geological conditions of permafrost in Northeast China, combined with the change of the mechanics parameters of runway structure with temperature, a hydrothermal-mechanical coupled two-dimensional finite element model of runway foundation was established. Finally, the distribution law of the overall temperature stress of the runway surface structure and the foundation in January, April, July and October during the 30 years was calculated. The results show that the method of calculating the temperature field of frozen soil based on the finite element simulation of hydro-thermal coupling is effective. The influence depth of horizontal temperature stress in the middle of the runway is about 5 m. The temperature stress changes significantly in January and July during the year, and temperature compressive stress exists in most of the permafrost foundation, and it increases year by year. The maximum temperature tensile stress in the pavement structure layer appeared in the center surface of the runway in January, which was about 30% of the split strength of the surface material, and appeared in the base of the runway in July, which was about 28% of the split strength of the base material. It can be seen that temperature stress of permafrost runway foundation need attention in summer and winter. The above results can provide reference for airport runway design in permafrost environment.

Key words: road engineering, temperature stress, finite element simulation, permafrost, airport runway