The Oaky Creek North Mine is part of the Oaky Creek coal complex located in the Bowen Basin of Queensland, Australia. The complex comprises several underground and open-cut mines, including Oaky North and Oaky No. 1 mine, which have historically produced high-quality coking coal primarily used in steel production.
The project faced significant challenges with a weathered zone extending down to 40 meters below the surface and an unsupported shaft diameter falling short of the 2.4-meter minimum requirement. In addition, the construction of a concrete collar cap was needed to support the excavation of the shaft and fan. A critical safety concern was also identified with the presence of methane gas at the shaft location, necessitating a comprehensive solution to manage this risk effectively.
MDA addressed the project’s challenges with a comprehensive strategy, initiating with an in-depth geotechnical analysis of the weathered zone to evaluate its impact on shaft stability. To ensure the shaft’s long-term integrity, a structural design featuring steel liners extending down to 40 meters was crafted. Concurrently, an integrated collar cap was engineered for crucial excavation support, complemented by a bespoke live trending gas monitoring system to continuously manage methane levels, upholding the safety of the raise bore team throughout operations.
The collaborative efforts resulted in the successful application of the Engineering, Procurement and Construction (EPC) model. The steel liners, tailored to the project’s specifications, were designed, manufactured and installed with precision, effectively securing the shaft’s structure. The construction of the collar cap was executed flawlessly, reinforcing the excavation support. Most importantly, the innovative gas monitoring system allowed for real-time management of methane levels, ensuring safe operational conditions during the shaft excavation process. This case study exemplifies MDA’s ability to deliver comprehensive solutions that meet the stringent safety and engineering requirements of complex mining operations.
Design & quality assurance of collar cap
Install drill pipe down existing pilot hole 255m
Back ream of shaft to 2.4m diameter
Design, supply & install steel liners 40LM
Remote shotcrete poor ground & coal seams 75LM
