5
total of 5 ravel stages were modeled before the DFN reaches
a final configuration where no more fracture networks can
be traced within the tensile zone. The 5 ravel stages are pre-
sented in Figures 10 through 14.
Bolting Analysis
The final configuration of the raveling stage (Figure 14)
represents the mass of rock which would mobilize in shear
when undercut and must be supported to manage stope
shoulder stability. Due to the horizontal orientation which
any bolts would be installed into the TC ribs, bolt strengths
must account for oblique loading rather than tensile
Figure 9. Tensile zones overlaid on the DFN simulation
loading. Bolt shear strengths, as a percentage of their tensile
strengths, are presented below and are tabulated in Table 2.
• Friction bolts (Split Sets, Swellex, and Super Swellex)
=50% (Dight, 1982)
• Cable bolts =60% (Li, et al., 2014)
• Solid steel bar (threaded rebar, forged head rebar, and
Dywidag types) =70% (McHugh &Signer, 1999)
Figure 10. Ravel Stage 1 Figure 12. Ravel Stage 3
Figure 11. Ravel Stage 2
total of 5 ravel stages were modeled before the DFN reaches
a final configuration where no more fracture networks can
be traced within the tensile zone. The 5 ravel stages are pre-
sented in Figures 10 through 14.
Bolting Analysis
The final configuration of the raveling stage (Figure 14)
represents the mass of rock which would mobilize in shear
when undercut and must be supported to manage stope
shoulder stability. Due to the horizontal orientation which
any bolts would be installed into the TC ribs, bolt strengths
must account for oblique loading rather than tensile
Figure 9. Tensile zones overlaid on the DFN simulation
loading. Bolt shear strengths, as a percentage of their tensile
strengths, are presented below and are tabulated in Table 2.
• Friction bolts (Split Sets, Swellex, and Super Swellex)
=50% (Dight, 1982)
• Cable bolts =60% (Li, et al., 2014)
• Solid steel bar (threaded rebar, forged head rebar, and
Dywidag types) =70% (McHugh &Signer, 1999)
Figure 10. Ravel Stage 1 Figure 12. Ravel Stage 3
Figure 11. Ravel Stage 2