Duncan Robert Lees
Senior Rock Engineering Consultant
Benoni,Gauteng
Summary
Experienced Rock Engineering Specialist with over 18 years in underground, open cast, and coal mining. Legally appointed to numerous quarries, underground mines, and surface operations. Proven leader in developing geotechnical frameworks, risk management systems, and codes of practice. Skilled in slope stability, underground support design, hazard management, and feasibility studies across coal, hard rock, and quarry environments. Currently leading geotechnical consulting and advisory services nationwide.
Overview
18
18
years of professional experience
5
5
years of post-secondary education
Work History
Director & Principal Consultant
Geomech Consulting (Pty) Ltd
01.2013 - Current
- Provide geotechnical governance, design, and advisory services across multiple operations (underground and surface).
- Develop and audit geotechnical codes of practice and management systems.
- Conduct technical reviews, ground control hazard mapping, and risk assessments.
- Lead site-based and remote support for DMRE compliance, layout designs, and project scoping.
Senior Rock Engineer & Director
Associated Rock Mechanics (ARMS)
01.2013 - Current
- Lead technical projects and coordinate multi-site geotechnical support services.
- Oversee audits, ground condition monitoring, and design validation for open pit operations.
Geotechnical Manager
Total Coal South Africa (TCSA)
01.2010 - 01.2013
- Managed geotechnical functions for five coal mines (both underground and opencast).
- Led the Rock Engineering team and developed mine-specific support standards.
- Conducted site inspections, MROR reviews, and provided risk input on mine plans.
Senior Mine Rock Engineer
Exxaro Resources (Arnot Coal)
01.2008 - 01.2010
- Responsible for full geotechnical risk oversight and planning support.
- Delivered numerical modelling for underground stability and supported risk assessments for surface structures.
Rock Engineering P.I.T
Matla Coal & Anglo Coal
01.2007 - 01.2008
- Contributed to goaf blasting designs, numerical modelling, and highwall investigations.
- Gained experience across multiple coal operations and conditions.
Education
BSc (Hons) - Engineering Geology
University of Pretoria
04.2001 - 01.2006
Chamber of Mines Certificate in Rock Mechanics (Coal) - undefined
Chamber of Mines
Chamber of Mines Certificate in Strata Control - undefined
Chamber of Mines
Skills
- Ground control and support design
- Stability analysis and geotechnical hazard management
- Seismic monitoring and risk mitigation
- Numerical modelling and data interpretation
- Project management and technical report writing
- Leadership, team supervision, and mentoring
- Problem-solving and decision-making under pressure
- Health, Safety, and Compliance management
Key Projects And Achievements
- Implementation of high extraction mining across underground coal operations.
- Development of detailed geotechnical hazard plans for surface and underground mines.
- Structural slope design in varied geology (dolerite, tillite, granite, etc.).
- Technical lead for risk mitigation around sinkholes and dolomitic ground.
- Recognition awards for department development and innovations in GIS/geotechnical integration.
Leadership And Industry Involvement
- Geotechnical Manager, TCSA
- Director, ARMS & Geomech Consulting
- SANIRE Coalfields Branch Committee Member
Timeline
Director & Principal Consultant
Geomech Consulting (Pty) Ltd
01.2013 - Current
Senior Rock Engineer & Director
Associated Rock Mechanics (ARMS)
01.2013 - Current
Geotechnical Manager
Total Coal South Africa (TCSA)
01.2010 - 01.2013
Senior Mine Rock Engineer
Exxaro Resources (Arnot Coal)
01.2008 - 01.2010
Rock Engineering P.I.T
Matla Coal & Anglo Coal
01.2007 - 01.2008
BSc (Hons) - Engineering Geology
University of Pretoria
04.2001 - 01.2006
Chamber of Mines Certificate in Rock Mechanics (Coal) - undefined
Chamber of Mines
Chamber of Mines Certificate in Strata Control - undefined
Chamber of Mines
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