Mine Closure - Geotechnical Considerations
Western Australia
Assessing geotechnical stability in preparation for closure and rehabilitation.
Calibre QuadR was commissioned to assess the geotechnical stability of alluvial tailings dam post-closure landforms as part of a major mine closure project.
Project summary
Our geotechnics team assessed the stability and closure design of 5 ATDs in accordance with the ANCOLD and the clients D5 requirements.
The stability condition of each individual ATDs was assessed under designed water level and seismic events. The outcomes of the assessments were delivered as an interpretive report to address the client’s requirements.
Project need
The key project requirements were:
- Review and compile all available geotechnical data
- Assessment of long term structural integrity of the landforms
- Assessment of stability of landforms against the client and ACOLD standards
Project solution
The team considered an approach to address the client’s requirements including:
- Desk study and review of the existing geotechnical information and relevant standards
- Dam risk classification, stability assessment of ATDs under different water levels, seismic loads, and liquefaction potential
Outcomes
Calibre QuadR delivered a conceptual schedule of works and cost estimate for the geotechnical investigations and interpretation for different major track shuts as well as the following project outcomes:
- Memorandums on development of slope stability models
- Interpretive report including methodology of study, assessment results, and their interpretation
Value add
Our assessment confirms that the proposed closure designs at an overall embankment scale meets geotechnical completion criteria.