4
the same rock type (Poorman). Figure 4 shows the ramp in
cross-section and the three major rock formations present.
Step 3 FEM Execution and Results The runstream file
produced during mesh generation is
HME Drift energy to failure equiprops 4/23/2023 zigzag
Studio 2010\Projects\SPK\GMB3\EQHMEdrift.txt
F:\Visual Studio 2010\Projects\SPK\GMB3\belms
F:\Visual Studio 2010\Projects\SPK\GMB3\bcrds
F:\Visual Studio 2010\Projects\SPK\GMB3\brcte
F:\Visual Studio 2010\Projects\SPK\GMB3\bsigi
F:\Visual Studio 2010\Projects\SPK\GMB3\bnsps
HMRz
nelem =907200
nnode =945504
nspec =53064
nmat =3
ncut =-1
ninc =5
nisgo =1
inter =200
maxit =4000
nyeld =2
nelcf =14400
nsol =2
nprb =9
mgob =0
error= 1.0000
orf =1.8600
xfac =12.0000
yfac =12.0000
zfac =12.0000
efac =1.0000
cfac =1.0000
tolr% =0.0100
ENDRUN
Figure 5 shows the distribution of element safety fac-
tors in a cross section at the top of the ramp and Figure 6
shows the element safety factor distribution in a long sec-
tion. The distribution changes little with additional depth
which is not too surprising since the change in depth going
down the ramp is only an additional 75 ft. Depth of the
section is approximately 4,850 ft. Some bolting and per-
haps screening is indicated by the failures at corners and
shoulders of the ramps
EXAMPLE–SPIRAL RAMP
This example is inspired by a ramp at the famous Lucky
Friday Mine in the Coeur d’Alene Mining District of
Northern Idaho (Williams et al 1992). As usual, the study
process proceeds in three steps.
Step 1 Preparation of a materials property file The equiva-
lent properties are (units are as before):
NLYRS =3
NSEAM =2
(1) Vitreous Quartzite N50W 70SW
0.272E+06 0.624E+05 0.350E+06 0.10 0.01 0.21
0.479E+05 0.161E+06 0.342E+05 0.00 0.00 0.00
5172.5 2477.4 5867.8 591.1 283.1 670.6
1009.6 483.5 1145.3
220.0 70.0 4720.0 280.0
(2) Argillitic Quartzite modified for the HOOK at 5100
0.258E+06 0.620E+05 0.298E+06 0.11 0.01 0.18
0.473E+05 0.152E+06 0.340E+05 0.00 0.00 0.00
2106.0 1032.4 4976.7 691.3 338.9 439.5
696.6 341.5 853.9
220.0 70.0 5100.0 40.0
(3) Sericitic Quartzite
0.268E+06 0.623E+05 0.337E+06 0.10 0.01 0.20
0.478E+05 0.159E+06 0.342E+05 0.00 0.00 0.00
3858.9 1858.9 7557.9 514.7 247.9 444.1
813.6 392.0 1057.7
220.0 70.0 5240.0 280.0
Figure 4. An arched back ramp cross-section in dipping rock
formations indicated by the different colors. Grey elements
indicate the boundary of the ramp section. The section is
11 ft (3.3 m) wide and has a width to height ratio of one
the same rock type (Poorman). Figure 4 shows the ramp in
cross-section and the three major rock formations present.
Step 3 FEM Execution and Results The runstream file
produced during mesh generation is
HME Drift energy to failure equiprops 4/23/2023 zigzag
Studio 2010\Projects\SPK\GMB3\EQHMEdrift.txt
F:\Visual Studio 2010\Projects\SPK\GMB3\belms
F:\Visual Studio 2010\Projects\SPK\GMB3\bcrds
F:\Visual Studio 2010\Projects\SPK\GMB3\brcte
F:\Visual Studio 2010\Projects\SPK\GMB3\bsigi
F:\Visual Studio 2010\Projects\SPK\GMB3\bnsps
HMRz
nelem =907200
nnode =945504
nspec =53064
nmat =3
ncut =-1
ninc =5
nisgo =1
inter =200
maxit =4000
nyeld =2
nelcf =14400
nsol =2
nprb =9
mgob =0
error= 1.0000
orf =1.8600
xfac =12.0000
yfac =12.0000
zfac =12.0000
efac =1.0000
cfac =1.0000
tolr% =0.0100
ENDRUN
Figure 5 shows the distribution of element safety fac-
tors in a cross section at the top of the ramp and Figure 6
shows the element safety factor distribution in a long sec-
tion. The distribution changes little with additional depth
which is not too surprising since the change in depth going
down the ramp is only an additional 75 ft. Depth of the
section is approximately 4,850 ft. Some bolting and per-
haps screening is indicated by the failures at corners and
shoulders of the ramps
EXAMPLE–SPIRAL RAMP
This example is inspired by a ramp at the famous Lucky
Friday Mine in the Coeur d’Alene Mining District of
Northern Idaho (Williams et al 1992). As usual, the study
process proceeds in three steps.
Step 1 Preparation of a materials property file The equiva-
lent properties are (units are as before):
NLYRS =3
NSEAM =2
(1) Vitreous Quartzite N50W 70SW
0.272E+06 0.624E+05 0.350E+06 0.10 0.01 0.21
0.479E+05 0.161E+06 0.342E+05 0.00 0.00 0.00
5172.5 2477.4 5867.8 591.1 283.1 670.6
1009.6 483.5 1145.3
220.0 70.0 4720.0 280.0
(2) Argillitic Quartzite modified for the HOOK at 5100
0.258E+06 0.620E+05 0.298E+06 0.11 0.01 0.18
0.473E+05 0.152E+06 0.340E+05 0.00 0.00 0.00
2106.0 1032.4 4976.7 691.3 338.9 439.5
696.6 341.5 853.9
220.0 70.0 5100.0 40.0
(3) Sericitic Quartzite
0.268E+06 0.623E+05 0.337E+06 0.10 0.01 0.20
0.478E+05 0.159E+06 0.342E+05 0.00 0.00 0.00
3858.9 1858.9 7557.9 514.7 247.9 444.1
813.6 392.0 1057.7
220.0 70.0 5240.0 280.0
Figure 4. An arched back ramp cross-section in dipping rock
formations indicated by the different colors. Grey elements
indicate the boundary of the ramp section. The section is
11 ft (3.3 m) wide and has a width to height ratio of one