Modelling the Behaviour of Freezing and Thawing Soil Slopes

Mass movement processes on soil slopes where the ground thermal regime is dominated by seasonal freezing and thawing is often characterised by widespread periglacial solifluction (gelifluction) and shallow landslides. Observations in permafrost regions show that when ice-rich frozen slopes thaw, high moisture contents, raised pore water pressures and significant loss of strength results causing a detrimental effect to the stability of the slope through an increase in slope mass and reduction in effective stress. A Thermo-Hydro-Mechanical (THM) coupled theoretical formulation that incorporates an elasto-plastic Camclay stress-strain constitutive relationship is presented. Furthermore a numerical solution of this formulation and results of its application to a simple soil column during an annual cycle of freezing and thawing are presented.