4
approaches that the mine operator used to successfully
complete the pit.
Prism Array
From 2011 to mid-2012, the mine utilized a total station
and prism array to monitor the high walls in the pit. These
prisms were installed on all the walls at regular distances to
provide continuous displacement monitoring. Additional
prisms were installed along the north haul road as well.
The prisms were monitored via two robotic total sta-
tions (RTS) that were controlled remotely. The RTS units
were housed in a climate-controlled shack and all data was
able to be remotely viewed and assessed. The software used
with this setup also provided the ability to create alarms
should movement thresholds be reached.
However, the prisms did not perform well in an envi-
ronment with rapid and constant slope deformations.
Prisms were routinely lost due to rock fall strikes or failing
benches. Replacement of lost prisms was not usually pos-
sible due to no safe access points for personnel.
In 2012, it was decided that a more robust monitor-
ing device was needed that would not require personnel to
enter failing areas.
In 2012, the mine purchased a slope monitoring radar
unit. The unit was mobile, had the ability to run via an
onboard generator or be tied into an existing electrical
power supply, and did not need targets or prisms installed
on the high wall.
One advantage of the radar unit was that it would dis-
play exactly what sections of the high wall showed move-
ment. This was key in both determining where mining
activities could or could not be performed, but also aided
the Geotechnical Department in determining which, if any,
faults, or structures could be involved in the movement.
A second advantage of the radar unit was the speed
at which it could scan the high walls and provide the lat-
est information. On average, the radar unit would scan
about half of the pit in about five minutes. This was a huge
improvement over the prism array, which would only be
able to scan every 30 to 40 minutes.
The software associated with the radar unit allowed the
Geotechnical Engineers to set up tighter alarms for areas
showing movement. The software was also flexible, enabling
the use of multiple alarm areas within the same scan region.
This tailored approach meant that appropriate alarms could
be added to each individual area, without the need to apply
a single, overly conservative value to the entire pit.
Figure 6. Topographic map indicating prism locations
throughout the pit (Yang, 2013). Slope Monitoring Radar
Figure 7. Screenshot of heat map created by the slope
monitoring radar unit (Yong, et al, 2022).
approaches that the mine operator used to successfully
complete the pit.
Prism Array
From 2011 to mid-2012, the mine utilized a total station
and prism array to monitor the high walls in the pit. These
prisms were installed on all the walls at regular distances to
provide continuous displacement monitoring. Additional
prisms were installed along the north haul road as well.
The prisms were monitored via two robotic total sta-
tions (RTS) that were controlled remotely. The RTS units
were housed in a climate-controlled shack and all data was
able to be remotely viewed and assessed. The software used
with this setup also provided the ability to create alarms
should movement thresholds be reached.
However, the prisms did not perform well in an envi-
ronment with rapid and constant slope deformations.
Prisms were routinely lost due to rock fall strikes or failing
benches. Replacement of lost prisms was not usually pos-
sible due to no safe access points for personnel.
In 2012, it was decided that a more robust monitor-
ing device was needed that would not require personnel to
enter failing areas.
In 2012, the mine purchased a slope monitoring radar
unit. The unit was mobile, had the ability to run via an
onboard generator or be tied into an existing electrical
power supply, and did not need targets or prisms installed
on the high wall.
One advantage of the radar unit was that it would dis-
play exactly what sections of the high wall showed move-
ment. This was key in both determining where mining
activities could or could not be performed, but also aided
the Geotechnical Department in determining which, if any,
faults, or structures could be involved in the movement.
A second advantage of the radar unit was the speed
at which it could scan the high walls and provide the lat-
est information. On average, the radar unit would scan
about half of the pit in about five minutes. This was a huge
improvement over the prism array, which would only be
able to scan every 30 to 40 minutes.
The software associated with the radar unit allowed the
Geotechnical Engineers to set up tighter alarms for areas
showing movement. The software was also flexible, enabling
the use of multiple alarm areas within the same scan region.
This tailored approach meant that appropriate alarms could
be added to each individual area, without the need to apply
a single, overly conservative value to the entire pit.
Figure 6. Topographic map indicating prism locations
throughout the pit (Yang, 2013). Slope Monitoring Radar
Figure 7. Screenshot of heat map created by the slope
monitoring radar unit (Yong, et al, 2022).