Winter months can bring drastic changes to the stability of highwalls due to freezing and thawing. Water accumulates in crevices of rocks and then freezes. The ice acts as a wedge to expand the crevice opening. The ice thaws and the cycle begins again which in turn compromises the stability of the highwall that can result in highwall failure.
MSHA has issued a Safety Alert that can easily be printed out and posted or used in a toolbox talk.
Click here for: MSHA Safety Alert: Highwall Stability