Studies on the Mechanism of Frost Pillars Growth

Abstract

The growth of frost pillars are thought to be governed by both physical properties of soil and heat flux surrounding the soil. This research was conducted to study the mechanism involved in the growth of the frost pillars. This paper is consist of two parts. In the part one an experiment was carried out to obtain empirical data on the growth rates of the frost pillars, on changes in temprature on the top of the frost pillars, and on changes in soil water potential during the frost pillars growth period. Part two describes a construction of a numerial simulation model for coupled heat and moisture transfer during the frost pillar growth. The growth rate of the frost pillars and temprature at the top of the frost pillars were estimated based on the solution by numerical integration of the equation of heat conduction. The heat flux was considered as boundary conditions to solve this equation. Since the water transfer over time is non-linear, method of difference was used to simulate changes in water potential of the soil. Simulation was in reasonable agreement qualitatively withempirical data obtained in the previous part.