Transcript PRES TITLE IN ARIAL BOLD 40PT CAPS KEY

Laser Scanning at Mogalakwena
Platinum Mine-South Africa
Presented by
David van Rensburg
Geotechnical Department
Mogalakwena Platinum Mine
AngloAmerican PLATINUM
Geospatial World Forum
18-21 January 2011
1
PLATINUM
CONTENTS
• Overview, Mogalakwena Platinum Mine Regional Locality
• Mining Environment
• Riegl LPM321 Laser Deployment
• Slope Monitoring strategy used at Mogalakwena Mine
• The 6th Dec 2009 bench failure event
• Conclusions
2
PLATINUM
Mogalakwena Platinum Mine-Regional Locality
3
PLATINUM
Mining Environment
Brittle hard rock, highly jointed, toppling failure
4
PLATINUM
Riegl LPM321 Laser Deployment
Riegl control point
Blast shelter
High transmissivity glass
5
PLATINUM
Riegl LPM321 Laser Deployment
•
Mogalakwena Platinum Mine the first open pit in the world to use
lasers for slope stability monitoring.
•
Fully automated system developed in 2005.
•
Forms part of an integrated risk monitoring system, used mainly to
determine long term slope deformation trends and to identify high risk
areas.
•
Scanning locations determined by the mine Geotechnical Department.
•
Manual mode medium range profiling of surfaces, at distances up to
600m, although designed to operate up to distances of 6 000m at
accuracy of 20mm.
•
Scanning of highwalls done during daylight hours only because of
security concerns.
6
PLATINUM
Slope Monitoring strategy used at Mogalakwena Mine
Must have human intervention to initiate evacuation
Management Control
GeoMoS
Special Areas Committee
Management of Potentially Unstable
Areas
Riegl Laser
Photogrammetry
Evacuation initiated
automatically,
without human
intervention
Safety Critical
Monitoring
Routine daily functions
Extensomet
er
Identification of
Critically Unstable
Areas
GroundProbe SSR
Daily Visual
Inspections
Pit Alarms
Detailed
Inspections
Evacuation
Procedures
Specialised technical
investigations
7
PLATINUM
The 6th Dec 2009 bench failure event
•
Localised bench failure (700 tonnes) occurred on 6th Dec 2009, failure
mode was Toppling failure.
•
Initial slope movement (30m to the south of the failure) identified by
the laser 3rd week in November.
•
Slope stability radar deployed immediately.
8
PLATINUM
Scanning data East Highwall,recording of the 6th Dec 2009 failure event,
screen shot acquired 15th February 2010
9
PLATINUM
Scanning data East Highwall,recording of the 6th Dec 2009 failure event,
screen shot acquired 5th Dec 2009
10
PLATINUM
Scanning data East Highwall,recording of the 6th Dec 2009 failure event,
sharp deviation in the graph shows the failure event
11
PLATINUM
Conclusions
•
Although the laser did not locate any movement in the failure area, it
identified the precursor to the event almost a month earlier.
•
Slope stability radar was able to provide 20 hour warning of the failure
event, personnel were timeously evacuated.
•
The integration of laser together with slope stability radar provides an
effective and appropriate risk management system.
•
The reputational and economic cost to any mining organization when
personnel are injured or killed or equipment damaged or destroyed,
are immense.
•
The Riegl laser system plays a vital role in Mogalakwena’s approach to
open pit risk management.
12
PLATINUM
THANK
YOU
13