Linear models give relatively fast, but not very accurate estimate of the true material response. These models can be used in cases, where only the stress or deformation states of a soil mass are of interest. They provide no information about locations and possible mechanisms of failure.
They can be used to model soil behavior in regions, where only the local failure with no effect on the evolution of global failure occurs, but which may cause premature loss of convergence. Providing the main interest is in a reliable description of the soil behavior it is necessary to employ nonlinear models.
The linear models include: