Updates every Sunday
This an underground stope collapse - a common problem when you are opening up a new open pit over old underground workings - where records are poor, or non-existent. If large stopes are known to exist, from old underground workings plans, they are delineated and worked around. The other problem is when underground workings maps are known - but when there has been an underground fall or collapse between levels. Most stope collapses generally just mean a hole opening up in the floor, which is rarely big enough for a whole item of equipment to fall through. However, you don't want to look down, you can often see a large cavern. Most stopes in oxidised ground (surface to approximately 30-50 metres in Australia) aren't large - but they're dangerous because of the inherent ground instability. Once you're down into the hard rock, stopes are larger, but the rock is stable.
Subscribe in a reader