Study on Influencing Factors of Bearing Performance of Pile Foundations in High-Altitude Permafrost Environments and Their Engineering Applications

Abstract

High-altitude permafrost regions are characterized by low temperatures, intense freeze–thaw cycles, and pronounced temperature sensitivity. Changes in the permafrost environment can easily lead to the deterioration of the mechanical properties of soils, thereby affecting the long-term bearing performance and engineering stability of pile foundations. To clarify the variation law of pile foundation bearing performance and its major influencing factors under permafrost conditions, this study focuses on the pile–soil interaction mechanism and engineering application issues in high-altitude permafrost areas. First, the characteristics of the high-altitude permafrost environment and their effects on the mechanical behavior of pile foundations are analyzed, and the mechanisms by which freezing action, freeze–thaw cycles, and temperature variation influence shaft freeze-bond resistance and pile-tip bearing capacity are elucidated. Second, the effects of the physical and mechanical properties of frozen soil, temperature variation, freeze–thaw cycles, structural parameters of pile foundations, and loading conditions on the bearing performance of pile foundations are discussed. Finally, in combination with the engineering application characteristics in permafrost regions, key issues in the design, construction, and long-term service of pile foundations are analyzed. The results indicate that ground temperature variation and freeze–thaw cycles are the primary factors affecting the long-term stability of pile foundations. Permafrost degradation weakens the freezing effect at the pile–soil interface, thereby reducing shaft resistance and the overall bearing capacity. Therefore, in the construction of pile foundation projects in high-altitude permafrost regions, environmental changes, structural parameters, and long-term service effects should be comprehensively considered, and reasonable design and protective measures should be adopted to improve the safety and reliability of foundation engineering. The findings of this study can provide a reference for the optimization of pile foundation design and engineering application in high-altitude permafrost regions.