Abstract:To examine the impacts of freeze-thaw cycles on the performance of geogrid reinforced soil slope and the inhibition effect of reinforcement on sand slope deformation, two model tests were conducted on 1.2 m high slopes subjected to 7 freeze-thaw cycles under -25 ℃ and 30 ℃ conditions. The tests compared the performance of reinforced and unreinforced slopes, analyzing qualitative and quantitative variations in heat transfer, moisture migration, settlement, and lateral deformation of the slopes under freeze-thaw cycles. The results indicated that the slope temperature exhibited periodic changes during freeze-thaw cycles, with diminishing influence of external temperature from the free surface inward. During freezing, moisture migration within the slope occurred bidirectionally toward the free surface and base, while vertical migration predominated during thawing due to gravity. The slope settlement demonstrated periodic frost heave and thaw subsidence, with cumulative total settlement increasing with the number of freeze-thaw cycles. The slope displacement displayed freeze-expansion and thaw-induced contraction, and the total displacement increased with the number of freeze-thaw cycles. Reinforcement hindered vertical moisture migration within the slope, thereby changing the temperature field of the slope, and reinforcement effectively mitigated the deformation of the slope caused by freeze-thaw action.