To unify the source power of water migration

a pressure-suction element model of film water is constructed on the basis of the film water hydraulic driving force model and the surface adsorption force model. Model analysis shows that under the dual action of net suction and actual liquid pressure (or theoretical suction and actual ice pressure)

the surface adsorption force can be generated

which drives the tangential migration of water along the surface of the substrate. In view of the fact that the surface adsorption force has nothing to do with the boundary conditions

it is suitable for any form of unfrozen water

and it is the unified source power of water migration. Based on this

the pressure-suction element model is introduced into the frozen fringe theory

and it is found that the actual ice pressure determines the temperature and position of the segregated ice formation

the theoretical suction determines the direction of water migration

and the surface adsorption force determines the velocity of water migration. Finally

substituting the main parameters from the Konrad (1980) test into the surface adsorption force equation

it is found that even if the temperature gradient increases from 0.1 ℃/cm to 0.67 ℃/cm

the sample height increases from 6.4 cm to 28 cm

as long as the segregation freezing temperature and the overburden pressure keep unchanged

the surface adsorption force is always constant at ?23 kPa

which verifies the correctness of the surface adsorption force equation. In short

the development of this model has important theoretical value and practical significance for improving the existing frost heave theory and guiding engineering practice.