Mining in Manitoba

Undercut & Fill Mining

Engineering Considerations

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In the Undercut & Fill mining method, mining is carried on from the top down. The reason for doing this is to have some kind of artificial back or roof support of known strength characteristics so workers will not be exposed to overhead weak ore and wall rock.
To cut down on the amount of timber required and to provide a better overhead structure, cemented sandfill is used.This method is similiar to the Cut & Fill method, except that after the cut has been completed, heavy caps or stulls are placed on the floor of the cleaned out cut. They are wedged and pinned firmly in place. The stulls are placed 5-6' apart. Wire mesh and fabrene is installed on top of the stulls then sandfill is poured in.

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This method requires much more timber preparation than the ordinary untimbered cut & fill. However, the absence of posts increases the efficiency of mucking equipment.

In wider undercut & fill stopes, 8' panels are mined and filled individually, until the complete cut is mined out.