Around 100 tonnes of rocks collapsed into an open stope brow during a recent incident at an underground mine. The ground failed while a drill rig was being used to clean a production hole. The rig’s operator was uninjured, but employees had been preparing production holes for explosives in the area below the collapsed ground just hours before.
The ore drive had several modes of ground support in place, including split sets, cable bolts and shotcrete. These were all installed to industry accepted standards. Routine inspections of the site prior to the incident had not identified any abnormal geological or geotechnical issues. After the incident, the area was isolated to allow further geotechnical investigation.
Under the Occupational Health and Safety Regulations 2017 (OHS Regulations), mine operators must, so far as is reasonably practicable, identify all mining hazards at their mine and assess the risks to health and safety from those hazards. Mine operators must also implement risk controls that eliminate risks so far as is reasonably practicable, or where eliminating risks is not possible, reduce the risks so far as is reasonably practicable. In addition, the OHS Regulations set out the hierarchy of controls which must be considered when deciding on the risk controls to be implemented.
The OHS Regulations also require mine operators to develop and apply safety management systems (SMS) as the primary way to ensure safe operation of their mine. Operators must also review, and if needed, revise their SMS at least once every three years.
Please note that this alert does not outline all obligations that mine operators have under Victorian occupational health and safety laws, including the OHS Regulations. It is your responsibility to ensure that you comply with all of these obligations.
Planning for safety
When developing, reviewing and implementing their safety management system, mine operators should consider the following:
Before work commences:
- ensure work to be undertaken is planned
- install ground supports using recommended techniques and procedures
- complete geotechnical inspections and assessments for areas needing additional ground support
- identify potential rock falls during safety assessments and devising control measures
Employees must also be provided with information, instruction and training that covers mine ground support techniques, standards and procedures.
During work in underground mines:
- routinely inspect active underground mine workings
- ensure ground support activities are completed in line with planned ground support specifications and methodology
Additionally, regular rock fall and ground support information and training must be provided to employees to enable early detection of rock fall hazards and to assess the suitability of ground supports.