After defining the general dimensions of a retaining wall, click Next. The following dialog displays:
You can select one of the following geometry types for the retaining wall footing:
retaining wall with straight footing 
retaining wall with footing of varying height.
Once you click 
, the retaining wall footing with a key will be generated.
The lower part of the dialog includes the dimensions which defines the geometry of the retaining wall footing. A number of dimensions will change, based on the type of retaining wall footing selected.
After completing definition of dimensions of the retaining wall footing and clicking Next, the Retaining wall - Shelves dialog displays.