Surface Settlement of Deep Foundation Pit Considering the Influence of Excavation and Freeze–Thaw

In order to address the issue of surface deformation in wintering foundation pits in seasonal frozen soil areas due to excavation and freeze–thaw, an indoor scale model test was conducted to examine the displacement relationship between pit wall soil and supporting structures under freeze–thaw conditions, as well as the temperature change and water migration of soil surrounding the foundation pit. The distribution mode of surface settlement under excavation and freeze–thaw conditions was examined and a surface settlement calculation model was established based on the maximum value of surface settlement. The water will move from the frozen to the unfrozen region as a result of the freeze–thaw cycle. About 1.1 m is the freezing depth. An increase in surface settlement will result from the coordination of deformation between the soil and the supporting structure during freezing and thawing. The greatest surface settlement value following the initial freeze–thaw cycle is 1.082 mm, which is around 215% greater than that of excavation. The skewed distribution is comparable to the surface settlement curves produced by excavation and freeze–thaw cycles. The calculated model’s results and the measured settlement values agree rather well.