Mechanism of Pile-Soil Relative Vertical Displacement under the Freeze-Thaw Action

To effectively mitigate the risk of freeze-thaw disasters, the lines, poles, and piles in point-line constructions need be deployed with careful consideration of the compaction degree control of backfilled soil. Vertical displacements of soil and piles occur at the same time under freeze-thaw action, thereby making it difficult to determine the frost heave and thaw subsidence of piles. To solve this problem, we monitored the vertical displacements of piles and soil simultaneously and found that the pile-soil interaction differs, depending on the variances in backfill density. Such displacement also ultimately results in “pile-soil” system modification synchronization. To determine the vertical displacement of the pile foundation, one must first determine the relative displacement of the pile and soil. This work presents serial experimental results and verifies experimentally that an optimal degree of soil compaction exists in which the pile shows minimal changes in its vertical displacement.