Excavations, Stockpiles, Tips and Ground Stability
Excavations
Excavations must be assessed for collapse, and supported or battered back to a safe angle where people work. Keep spoil and plant back from the edge (a common rule of thumb is a set-back at least equal to the depth, and never less than the site's defined distance). Provide barriers and signage, prevent falls, control water, and locate buried services before digging - use plans, locators and safe digging practice. Access and egress by ladder in deeper excavations.
Stockpiles
Stockpiles are unstable at the toe and crest. Never work under an overhanging face of a stockpile, never remove material from the toe in a way that undercuts it, and keep plant and people back from the edge. Beware of entrapment in draw-off points and of collapse when material is wet or frozen.
Tips and lagoons
Tips and lagoons are controlled by the Quarries Regulations: a geotechnical specialist, a written scheme of examination, and inspections by a competent person at defined intervals (and after significant events such as heavy rain). Question traps: assuming a tip is stable because it looks stable; ignoring changes in water content; failing to record inspections.
Rule of thumb
If you would not stand under it, do not drive a machine under it either. Ground that has been disturbed is never assumed stable - it is assessed.