Abstract: To evaluate the deformation and failure of a transmission-line tower foundation and develop appropriate mitigation strategies, a comprehensive investigation was carried out using field measurements, surveys, subsurface explorations, and geophysical techniques. The study defined the extent of the foundation’s deformation, analyzed its underlying mechanisms, and identified the key contributing factors. Findings show that the deformation and failure resulted from creep-related sliding of the overlying permafrost in the slope direction, triggered by repeated freeze-thaw cycles. This represents a characteristic engineering-geological issue associated with special soil conditions in permafrost regions. Based on these results, two categories of countermeasures are recommended: rerouting the transmission line to avoid potential structural conflicts or implementing engineering treatments at the existing site to reduce frost heave and limit permafrost creep, thereby stabilizing the tower foundation.

Key words: Permafrost, Transmission Lines, Creep Slip, Freeze-Thaw and Thaw-Subsidence, Deformation and Failure, Treatment Countermeasures