7
• Ribs: 3 each (per side) twin strand cable bolts (10ft)
on 5ft centers (in addition to primary bolts). This
allows for 2.5 feet of embedment beyond the stope
shoulder (7.5 feet wide) to mobilize the tensile capac-
ity of the cable bolts.
• Back: 3 each Super Swellex or twin stand cable bolts
(10ft) on 6.5ft × 6.5ft centers (in addition to primary
bolts).
A general arrangement of the adopted secondary sup-
port is presented in Figure 17.
ALTERNATIVE CONDITIONS
The DFN simulation is controlled by lengths and spac-
ings of the mapped joints. Understanding their statistics
(standard deviation, minimum and maximum spacing and
length) is critical. For example, the conditions modeled as
part of the case study can yield vastly different results if
the lengths are shorter (3 feet) and the spacings are wider
(3 feet) as presented in Figure 18.
The DFN model presented in Figure 18 does not
generate any pathways by which a raveling sequence may
propagate. This is an example where the rock structure is
Figure 16. TC width plotted against safety factor by bolt type
Figure 17. Adopted secondary support and TC configuration
• Ribs: 3 each (per side) twin strand cable bolts (10ft)
on 5ft centers (in addition to primary bolts). This
allows for 2.5 feet of embedment beyond the stope
shoulder (7.5 feet wide) to mobilize the tensile capac-
ity of the cable bolts.
• Back: 3 each Super Swellex or twin stand cable bolts
(10ft) on 6.5ft × 6.5ft centers (in addition to primary
bolts).
A general arrangement of the adopted secondary sup-
port is presented in Figure 17.
ALTERNATIVE CONDITIONS
The DFN simulation is controlled by lengths and spac-
ings of the mapped joints. Understanding their statistics
(standard deviation, minimum and maximum spacing and
length) is critical. For example, the conditions modeled as
part of the case study can yield vastly different results if
the lengths are shorter (3 feet) and the spacings are wider
(3 feet) as presented in Figure 18.
The DFN model presented in Figure 18 does not
generate any pathways by which a raveling sequence may
propagate. This is an example where the rock structure is
Figure 16. TC width plotted against safety factor by bolt type
Figure 17. Adopted secondary support and TC configuration