The Frozen and Unfrozen Soil model constitutes a soil model implemented in PLAXIS, capable of describing the mechanical behaviour of frozen soils as a function of temperature, up to the unfrozen state and vice versa. The present constitutive model is the result of a collaboration between the Norwegian University of Science and Technology (NTNU) and Plaxis bv. The aim of this model is to provide a reliable design tool to evaluate the influence of climate/temperature changes in a variety of engineering problems. The increase of engineering activities in cold regions, projects involving artificial ground freezing and consequences of global warming lead to geotechnical applications which deal with frozen/unfrozen ground.
Frost heave as a result of a long-term drop in air temperature
The constitutive model developed by Amiri, Grimstad, Kadivar & Nordal (2016) characterises the mechanical behaviour of frozen soils as a function of temperature, up to the unfrozen state and vice versa. The Frozen and Unfrozen Soil Model is implemented as a user-defined soil model (UDSM) in PLAXIS, using the fully coupled THM calculation options.
With the release of PLAXIS 2D/3D CONNECT Edition V20 Update 1 (January 2020), the PLAXIS User Defined Soil models are delivered with the PLAXIS installation. When enabling the Geotechnical SELECT Entitlement [GSE] when starting the PLAXIS application, this model becomes available in the Parameters tab when selecting "User-defined" for the Material model.
How to use a user defined soil model in PLAXIS
Plaxis User Defined Soil Models