A Numerical Approach to Simulate Soil Freezing and Frost Heave behind an Earth Retaining Structure

Design and construction of earth-retaining structures in cold regions require special consideration for potential impact of frost heave. During the freezing process, additional earth pressure can be generated by frost heave as a result of the formation and growth of ice lenses in soil. The additional earth pressure due to frost heave may cause unacceptable deformation of the structures - or even failure - if it is not properly considered in the design. This paper presents a numerical approach to simulate the freezing process and associated frost heave in soil. In this approach, soil is treated as a mixture of solid particles, unfrozen water, and ices. The expansion of soil due to frost heave is described mathematically using the Porosity Rate Function, where the porosity rate (i.e., change of soil porosity over time) depends on the water transport into the freezing zone, which is governed by the soil temperature, temperature gradient, and stress. The heat transfer and frost heave models have been incorporated into a finite element program for numerical simulations. The numerical approach was used to evaluate a concrete cantilever retaining wall under freezing conditions. The simulation yielded realistic results of ground and wall deformation.