Vertices of boundaries (i.e. External, Material, Water Table, Piezometric Line or Tension Crack), can be deleted, using the Delete Vertex option. Delete Vertex is available in the menu, toolbar, or as a right-click option for individual vertices.
To delete boundary vertices:
Select Delete Vertices from the toolbar or the Edit sub-menu of the Boundaries menu.
You can select individual vertices by clicking on them with the left mouse button, or you can select multiple vertices by drawing a window around them (click and hold the left mouse button, and drag to create a window).
When you are finished selecting, press Enter or right-click and select Done Selection.
All selected vertices will be deleted and all boundaries will be redrawn using the remaining vertices.
Right Click Shortcut
The Right Mouse button can be used as a shortcut to delete individual vertices. To do this:
Locate the cursor over a boundary vertex that you wish to delete.
Click the RIGHT mouse button, and the vertex will be "selected".
A popup menu will appear, from which you can select the Delete Vertex option.
Select Delete Vertex and the vertex will be deleted.