Webinar case study: Failure and recovery of George Fisher Mine fresh air raise

Join the Mining Society for their webinar: Case study: Failure and recovery of George Fisher Mine fresh air raise

About this event

George Fisher Mine recently saw the failure and recovery of one of its fresh air raises. The methods of recovery were unconventional but provided successful and exciting results.

16L-18L JJ75 Fresh Air Raise (FAR) commenced reaming in April 2021. The raise incurred significant failure above 18L (south-west failure profile). Failure was a combination of mucking horizon (18L) drive orientation, a dominant vertical joint and weak infill; allowing for continuous unravelling. The deterioration exists along the full raise profile.

Planned raise diameter was 3.7m and final profile in sections is >12m. The reamer head was pulled through on 16L by keeping the failed raise choke fed with raise bore fines and fall off. To recover the raise, material was lowered (raise bore fines and fall off), mucking from 18C, in five sections. Filling each section with concrete before lowering the next.

Time: 1.00pm - 2.00pm (Melbourne time)