The general model boundary conditions for flow, when set to open, will unintentionally overwrite surface settings that should prevent flow through this boundary locally. This includes:
This is not correct, and gives wrong results for e.g. a consolidation analysis in which the excess pore pressures should dissipate around a plate and its interface located on the soil’s surface.
When the model allows it, add a dummy soil block (e.g. weightless) so that the supposed to be closed interface is now not located on the model boundary. This trick does not work for a closed surface flow boundary, since these only work when activated on the model boundary.
This is solved since PLAXIS 3D 2013.00