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Managing voids through mine planning excellence

Our Mine Planning team is at the forefront of mining innovation, pioneering the development and use of an advanced void management system – an industry-leading solution that informs probing, drill pattern and blasting design. 




The holistic system gives our office and field-based teams immediate access to a central database of void information to support better, faster decision making and task optimisation.

Thiess General Manager WA/SA (Acting) Matt Henderson said the system focuses on capturing, monitoring and understanding existing voids to help our project team manage and backfill where required.

“It gives us and our client a clear understanding of the geological and geotechnical risks associated with the project and how to best address them,” Matt said.

“This flows from mine design into operations, enabling our project team to manage and mitigate risk to our people and delivery.”

Thiess Mine Planning Manager Ravi Achari said the system, design to enable verticle mining through extensive networks of underground voids (drives, development workings, workings, vertical rises and large slopes) was developed to improve safety and provide greater certainty in our delivery.

“The system was developed using insights and learnings from a number of technologies currently available on the market, but without integration were unable to provide the required outcome,” Ravi said.

“We also leveraged insight from our void officers and surveyors, and drill and blast, geotechnical and mine planning engineers.”

Ravi confirmed the new system enables his team to determine the right solution specific to each void.

“The system uses historical plans, probing and drilling data to survey the position and size of the old workings,” Ravi said.

“This includes checking the location and attributes of the voids we find against the recorded data to verify any changes in size or shape.”

“Our findings will then inform our safety zone and backfilling requirements.”

Incorporating over five-years of proven void management processes and procedures, the system delivers client benefits by enabling our team to mine additional tonnes.

“The system gives a precise delineation of the voids informing a more tailored drill and blast design that allows additional recovery of the commodity,” Ravi said.

“It has also enabled a reduction of probe drilling costs by up to 25 per cent, representing a substantial cost saving.”

To date the system has helped manage and treat over 25 kilometres of underground voids and stopes in Western Australia and is currently being leveraged to develop an integrated Drill and Blast reporting system for Thiess globally.