Our projects

Providing the Complex Infrastructure Needed to Build Better Communities

Southern Coalfields Ventilation Shaft

The Southern Coalfields Ventilation Shaft (SCVS) was constructed at a mine, 45km north-west of Wollongong. The new 5m finished diameter (6.2m drilled) shaft is the largest of its type ever blind bored in Australia and reaches new mine workings at a depth of 523m.

The completed shaft is smooth and fully lined with steel/concrete composite liners that are hydrostatically sealed. The shaft lining is designed to meet the mine ventilation requirements for a service life of 20 years.

Client

TBA

Year

2015

Region

NSW

Deep Drilled ventilation shaft

Hydrostatic Liner Segments Installed

Litres of Process Water Treated

Scope of Works

Detailed design, methodology and specification preparation for all aspects of construction of a blind-bored ventilation shaft to a depth of 523 m.
Surface works to facilitate construction and lining of the shaft, including electricity supply, process water supply and earthworks for settling ponds required for the reverse circulation process.
Construction of on-site facilities to precast and cure composite steel and concrete shaft lining segments.
Presink excavation and FRP concrete construction of complex shaft collar, footings for shaft ventilation mechanical equipment, and work platform for blind bore drilling rig.
Installation of composite concrete/steel line segments, grouting and sealing to give a hydrostatic, maintenance-free surface.
Design, construction and operation of a temporary chemical dosing and flocculation system to treat large volumes of process water to a standard fit for it to be discharged at project conclusion.

Complexity

The Bladhill Claystone layer close to the surface was a barrier between two ground water systems, which gave potential for high water flow into the drilled shaft. At deeper levels, below 400m, there was risk of stress-induced spalling failure in the shaft walls as drilling passed through the Stanwell Park and Wombarra claystone layers and the Coal Cliff Sandstone strata. The shaft design and drilling methodology thoroughly addressed these and other issues.

After completion of the drilling and lining process, 18 million litres of silt-laden process water needed to be treated to make it fit for discharge into local waterways. A temporary chemical dosing and flocculation plant was set up and the drilling water was passed through a centrifuge. The treatment process solution was highly effective at reducing turbidity levels to below the discharge limits.

Abergeldie received a “Safety Champion Award” from the client for the site establishment, pre-sink and FRP concrete construction works elements of the project, in acknowledgement of incident-free, strict observance of active mine safety work procedures.