unfailed

From un- +‎ failed.

unfailed (not comparable)

1. Not failed, or that has not failed.
   • 2021 April 7, “Lord Mair: earthworks recommendations”, in RAIL, number 928, page 11:

     ■ 51: Identify in two distinctly different microclimates, the following slopes: an over-steep, unfailed slope in plastic clay; a failed slope in plastic clay; an unfailed slope in low plasticity clay; a plastic clay embankment; and a granular embankment. [...].