Problem description

A (steady state) groundwater flow calculation determines the flow (flux), groundwater head and pore pressures in the nodes of an element. After that, the deformation calculation needs the stress data including the pore pressures in the stress points in order to perform the analysis.
For the stresses in an interface, the data should be taken from the “soil side of the interface”. However, in Plaxis 3D2012, this data is taken from the other side of the interface which is incorrect. In the latter case the pore pressures are determined based on the surrounding clusters’ (phreatic) settings and not based on the groundwater flow results.

Because of this issue the interface pore pressures after a steady state groundwater flow calculation in PLAXIS 3D2012 are not correct. This results in incorrect pressures on e.g. walls.

Solution

This is solved since PLAXIS 3D 2013.00.