The element mesh has a limited extent relative to the in-situ soil. In order to avoid any significant distorting influence from the edges of the mesh, it is necessary to ensure that they are at a sufficient distance from the modeled structure.
The following image provides guidelines for the dimensions of the soil section to be taken into account, based on [1].
Additional Notes
- In preliminary calculations, the size of the calculation section should be varied and the influence on the results analyzed. If the results change only slightly when the edge distances at the governing points are increased, the calculation section can be considered sufficiently large.
- It may happen that the dimensions of the calculation section are determined by the in-situ soil profile, for example, as a result of highly deformable soil layers.
- When selecting calculation sections that extend deeper and deeper, it is necessary to take into account the corresponding material properties, as the stiffness of the soil generally increases significantly with depth. If this is not considered when selecting the material laws and material parameters, unrealistically large displacements (for example, settlement of foundations) may occur. [1]