GWT + NSF
The frame "GWT" ("GWT + NSF") serves to specify the depth of groundwater table and the level of incompressible subsoil.
Frame "GWT" - without influence of NSF
If the option "Consider influence of negative skin friction" is set in the frame "Settings", then it becomes possible to enter parameters of the negative skin friction using the "GWT + NSF" frame - boundaries of the region, where the influence of negative skin friction is considered, or sliding region and its material and cohesion.
Frame "GWT" - with the influence of NSF