The project is located in Queensland, approx. 60 km northeast of Emerald.
We were engaged for the re-opening of a ventilation shaft required for the planned re-commencement of underground mine operations on the Crinum Mine project.
The shaft was closed 10 years ago. With 2 significant concrete ‘plug’ zones in between the previous backfill material that were deposited when the mine closed the shaft off.
Geology (artificial layer)
The concrete strength was 40-50 MPa, with weaker fill zones below
Scope of works:
Coring and gradually excavation of concrete plug layers
The above mentioned concrete plug layers had to reamed out and be gradually excavated to the 2.5m diameter size. Goal: to open the 6 meter diameter shaft in stages.
The shaft is 80 m deep from surface level, and Bauer Australia used an 84 m Kelly bar.
Construction Methods: Coring and excavation of concrete plug
Main Equipment: BAUER BG 40
Construction period: December 2021