8
during development works. Drawing plan is arranged not
to undercut a LWV, therefore, draw point below the PB4E
is planned to stop production in the end of May 2022 in
which pillar integrity is guaranteed. Conservatively, deci-
sion to stop mucking helps to stop propagation and sta-
bilised the mobilised zone. This is important as such
condition to mine against the cave not a common practice.
The TARP for controlling draw rates is being devel-
oped for PB4W. Unlike PB1E where the draw column
nearly excesses the LWV pillar, the PB2W height of draw
is below the allowable pillar height and the draw points age
relatively newer compared to PB1E.
CONCLUSION
Freeport Indonesia continues its footprint expansion to
new production blocks that connects to existing ore-flow,
ventilation, and drainage systems. The succession of devel-
opment activities is also shared with ore production from
another area.
Meticulously measure the interaction between the
impact of production through cave vertical progression to
current drifts development helps the company to increase
the confidence level of maintaining current production
rate safely while bringing a new area active with minimum
impact to the schedule.
This study will be useful for future development and
interaction of new area within similar condition.
Figure 11. Probe holes drilling program
ACKNOWLEDGMENT
The authors would like to thank PT Freeport Indonesia
for allowing the publication of the information includes in
this paper. We would also appreciate the support of DMLZ
Engineering Short Range Team and DMLZ Geotechnical
team.
The authors also thank the senior management of
Underground Mine Divisions (Mathew Sullivan and Anton
Priatna) and Geo-Engineering Division (Ardhin Yuniar
and Anton Perdana).
REFERENCES
Beck Engineering. 2024. DMLZ2024JAN09 PB4 Seismicity
and break back model and measured. Papua: Beck
Engineering.
Cumming-Potvin, D. W. (2018). A re-evaluation of the
conceptual model of caving mechanics. Caving 2018:
Proceedings of the Fourth International Symposium
on Block and Sublevel Caving (pp. 179–190). Perth:
Australian Centre for Geomechanics, Perth.
Webster, S., Snyman, L., Francois, N., &Saadatfar, M.
(2022). X-ray computer tomography and ground
condition at Northparkes cave edges to further under-
standing of caving mechanisms of strain and hydrau-
lic conductivity. Caving 2022: Proceedings of the
Fifth International Conference on Block and Sublevel
Caving (pp. 635–650). Perth: Australian Centre for
Geomechanics.
during development works. Drawing plan is arranged not
to undercut a LWV, therefore, draw point below the PB4E
is planned to stop production in the end of May 2022 in
which pillar integrity is guaranteed. Conservatively, deci-
sion to stop mucking helps to stop propagation and sta-
bilised the mobilised zone. This is important as such
condition to mine against the cave not a common practice.
The TARP for controlling draw rates is being devel-
oped for PB4W. Unlike PB1E where the draw column
nearly excesses the LWV pillar, the PB2W height of draw
is below the allowable pillar height and the draw points age
relatively newer compared to PB1E.
CONCLUSION
Freeport Indonesia continues its footprint expansion to
new production blocks that connects to existing ore-flow,
ventilation, and drainage systems. The succession of devel-
opment activities is also shared with ore production from
another area.
Meticulously measure the interaction between the
impact of production through cave vertical progression to
current drifts development helps the company to increase
the confidence level of maintaining current production
rate safely while bringing a new area active with minimum
impact to the schedule.
This study will be useful for future development and
interaction of new area within similar condition.
Figure 11. Probe holes drilling program
ACKNOWLEDGMENT
The authors would like to thank PT Freeport Indonesia
for allowing the publication of the information includes in
this paper. We would also appreciate the support of DMLZ
Engineering Short Range Team and DMLZ Geotechnical
team.
The authors also thank the senior management of
Underground Mine Divisions (Mathew Sullivan and Anton
Priatna) and Geo-Engineering Division (Ardhin Yuniar
and Anton Perdana).
REFERENCES
Beck Engineering. 2024. DMLZ2024JAN09 PB4 Seismicity
and break back model and measured. Papua: Beck
Engineering.
Cumming-Potvin, D. W. (2018). A re-evaluation of the
conceptual model of caving mechanics. Caving 2018:
Proceedings of the Fourth International Symposium
on Block and Sublevel Caving (pp. 179–190). Perth:
Australian Centre for Geomechanics, Perth.
Webster, S., Snyman, L., Francois, N., &Saadatfar, M.
(2022). X-ray computer tomography and ground
condition at Northparkes cave edges to further under-
standing of caving mechanisms of strain and hydrau-
lic conductivity. Caving 2022: Proceedings of the
Fifth International Conference on Block and Sublevel
Caving (pp. 635–650). Perth: Australian Centre for
Geomechanics.