Study on the Impact of Sudden Temperature Increase on the Hydrothermal Stability of Permafrost in Long-Term Permafrost Regions

With the advancement of the "Western Development" strategy, there has been an increasing trend in engineering construction in the Qinghai-Tibet Plateau region. This study, based on a high-altitude airport project in the hinterland of the Qinghai-Tibet Plateau, aims to investigate the impact of sudden temperature increases on the hydrothermal stability of natural ground in permafrost regions. By establishing a coupled hydrothermal model and integrating field measurement data, the study analyzes the effects of temperature spikes on the hydrothermal behavior of permafrost ground. The research reveals that sudden temperature increases lead to elevated ground temperatures in permafrost regions, resulting in an increase in unfrozen water content and changes in frost heave. Through numerical simulations and comparative analysis, it is found that temperature spikes significantly affect the hydrothermal behavior of ground materials, potentially causing uneven settlement of ground materials and thereby impacting the safety of surface structures. These findings hold significant implications for engineering construction and infrastructure design in permafrost regions, providing theoretical support and technical guidance for future projects in the area.