Abstract：Based on the idea of‘active cooling’，aiming at problems of frozen heaving and heat diffusion which commonly exist in frozen soil pile foundation，a new type of pile is proposed to overcome the disadvantages of the classical pile used in frozen soil. Pile body within active layer is fluted and refilled with porous materials such as gravels and ballasts. Thus convections occur and thermal exchanges inside porous materials in winter，but heat conduction exists only in summer because cold air is at the bottom of the fluting. As a result，the soil around flutings is cooled and the permafrost tables are raised. This paper analyses the cooling mechanism and feasibility and the temperature field of classical pile，and the new type of pile by numerical simulation. The results of numerical simulation indicate that the new type of pile can promote permafrost growth，accelerate the course of refreezing greatly after fluting via effect of natural convection for dropping temperature，help raising the permafrost table，and consequently enhance pile bearing capacity and its capability for resisting frost heaving and thaw settlement.
