Frost heave damage is caused by the in situ freezing of pore water and segregated ice due to moisture migration. Previous studies have shown that in freezing soil, moisture migration is related to the pore water pressure gradient, and moisture migration is the dominant reason for the formation of an ice lens. However, the essential relationship between ice segregation and the matric potential is still controversial. Using a pF meter sensor, a 5TM volume water content sensor, and a digital image capture system, the relationship between the matric potential and the unfrozen water in saturated freezing soil was monitored in real time, and digital images of the formation of segregated ice were collected. Furthermore, the time space coupling relationships between the unfrozen water, the matric potential, the frost-heaving amount, the moisture migration, and the formation of an ice lens were systematically analyzed during soil freezing. The results demonstrate that there is an internal relationship between the moisture migration driven by the matric potential (from the micro-perspective) and the segregated ice layer effect (from the macroscopic perspective). In addition, the unfrozen water and the matric potential in the frozen area have a significant impact on the distribution of the segregated ice lenses.

冻胀破坏是由于水分迁移导致孔隙水和冰块原位冻结而引起的。先前的研究表明，在冰冻的土壤中，水分迁移与孔隙水压力梯度有关，水分迁移是形成冰晶的主要原因。但是，冰离析与基质潜能之间的本质关系仍然存在争议。使用pF计传感器，5TM体积水含量传感器和数字图像捕获系统，可实时监测饱和冻结土壤中基质势与未冻结水之间的关系，并记录了分离冰形成的数字图像集。此外，未冻结的水，基质电势，结霜量，水分迁移之间的时空耦合关系，在土壤冻结过程中系统地分析了冰晶的形成。结果表明，由基质势驱动的水分迁移（从微观角度看）与偏析的冰层效应（从宏观角度看）之间存在内在联系。另外，在冻结区域中未冻结的水和基质势对分离的冰晶的分布有重要影响。