The choice of thematerial models for soils is limited in some finite element programs. The material models of the “linear elastic, ideal plastic” category can lead to incorrect predictions in the case of retaining wall structures – see, for example, (HÜGEL , 2005), (V ERMEER & W EHNERT, 2005) and recommendation E3-4 in (S CHANZ, 2006). The use of high-quality elastoplastic or hypoplastic material models is called for which can at least describe the main phenomena of the mechanical behaviour of soils:
- stiffnesses not dependent on pressure,
- different stiffnesses for unloading and reloading,
- shear behaviour for drained and undrained conditions,
- dilatancy behaviour.
For a detailed explanation of the main phenomena of the mechanical behaviour of soils, see, for example, (H ERLE &MAŠÍN, 2005) or (SCHANZ, 2006). High-quality material models may even be necessary during the feasibility studies for sheet piling structures.