Show Active Forces
The Show Active Forces 
option toggles the display of the active forces from the soil wedge pushing against the structure.
mode.
Active Failure Plane
The failure surface in the active region will only be visible when the active pressure methodology assumes a planar failure surface. This is rendered as a red line delineating the failure surface being considered in the currently selected failure. Log-spiral methods such as the Kerisel & Absi or Brinch Hansen (EN1997) will not render a failure plane.
Active Wedge
A shaded region behind the failure
plane corresponding to the region of soil that is pushing against the
region contained within the failure plane, along with the associated
driving forces.