This is a beam-like element that is a form of distributed Winkler Spring in both the transverse and longitudinal actions. These can be used to represent foundation material under a structure or to represent through-soil coupling between structures.

Shear stiffness terms are optional except for Vogt foundation model.

• A choice of almost any of the hysteresis rules available.
• Strength degradation is permitted for most hysteresis rules.
• Actions are only provided in the local x-y plane of the element.
  1. Vlasov soil model, linear variation with depth for shallow soils.
  2. Vlasov soil model, hyperbolic variation with depth for deep soils.
  3. Vlasov soil model, exponential variation with depth for very deep soils.
  4. Pasternak soil model, this is a general two-parameter model.
  5. Vogt soil model, a general model but with no shear term.