6
where depth is 5120 ft (1,5161 m). The ramp is in argillitic
quartzite (NSEAM=2).
Elastic and strength properties are anisotropic as evi-
dent in the file. Interestingly, the original properties are also
anisotropic. For example in case of argillitic quartzite,
(1) joint S70W 0.1 thik N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
350.0 65.0 0.5 -0.10
(2) joint N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
355.0 89.0 0.5 -0.10
(3) joint bedding plane N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
220.0 70.0 1.0 -0.10
(2) Argillitic Quartzite
4.2e+06 4.2e+06 1.8e+06 0.18 0.11 0.11
1.1e+06 1.1e+06 1.8e+06 0.0 0.0 0.0
8500.0 8500.0 12230.0 2790.0 2790.0 1080.0
2820.0 2820.0 2100.0
220.0 70.0 5980.0 40.0
where joint stiffnesses (moduli) are estimated as one per-
cent of the intact moduli and joint strengths are estimated
as ten percent of intact rock strength. Units are as before.
The depth of the argillitic quartzite is not important to the
calculation of equivalent jointed rock properties, only in
the finite element analysis following. The negative thickness
is a flag to the computer program indicating a joint.
Step 2 Mesh Generation Mesh generation input is given
in the InData file that is developed during mesh generation
for the drift section. Thus,
Input Data
"RAMPS" NPROB 9
Ramps Shape =Arched Rectangle
Ramp System =Single Opening
Ramp Width =11.0
Width/Height Ratio =1.0
Ramp Height= 11.0
Section Depth Seam Center (ft) =5120.0
Additional Sxx,Syy=,Szz,Tyz,Tzx,Txy, tension +=psi
-7721.0 -5774.0 -5906.0 0.0 0.0 0.0
Ramp Stress Sxx,Syy=,Szz,Tyz,Tzx,Txy, tension +=psi
-7721.0 -5774.0 -5906.0 0.0 0.0 0.0
0.0 0.0 0.0
No gravity stress is applied rather, the premining stress is
“additional” and based on formulas developed from many
in situ stress measurements (Board and Beus 1989).
A spiral ramp begins on a level grade and then begins
to decline according to the design grade in a circular path
for 360 deg or more as desired. Figure 7 shows the mesh
Figure 7. A cross-section of a spiral ramp with a design grade of 15 percent. The ramp is circular so sections are at 0, 180 and
360 deg are shown. The section is 11x11 ft (3.4x3.4 m). The spiral radius is 11.25 times opening width or 123.74 ft (37.7 m)
where depth is 5120 ft (1,5161 m). The ramp is in argillitic
quartzite (NSEAM=2).
Elastic and strength properties are anisotropic as evi-
dent in the file. Interestingly, the original properties are also
anisotropic. For example in case of argillitic quartzite,
(1) joint S70W 0.1 thik N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
350.0 65.0 0.5 -0.10
(2) joint N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
355.0 89.0 0.5 -0.10
(3) joint bedding plane N=2
4.2e+04 4.2e+04 1.8e+04 0.18 0.11 0.11
1.1e+04 1.1e+04 1.8e+04 0.0 0.0 0.0
850.0 850.0 1223.0 279.0 279.0 108.0
282.0 282.0 210.0
220.0 70.0 1.0 -0.10
(2) Argillitic Quartzite
4.2e+06 4.2e+06 1.8e+06 0.18 0.11 0.11
1.1e+06 1.1e+06 1.8e+06 0.0 0.0 0.0
8500.0 8500.0 12230.0 2790.0 2790.0 1080.0
2820.0 2820.0 2100.0
220.0 70.0 5980.0 40.0
where joint stiffnesses (moduli) are estimated as one per-
cent of the intact moduli and joint strengths are estimated
as ten percent of intact rock strength. Units are as before.
The depth of the argillitic quartzite is not important to the
calculation of equivalent jointed rock properties, only in
the finite element analysis following. The negative thickness
is a flag to the computer program indicating a joint.
Step 2 Mesh Generation Mesh generation input is given
in the InData file that is developed during mesh generation
for the drift section. Thus,
Input Data
"RAMPS" NPROB 9
Ramps Shape =Arched Rectangle
Ramp System =Single Opening
Ramp Width =11.0
Width/Height Ratio =1.0
Ramp Height= 11.0
Section Depth Seam Center (ft) =5120.0
Additional Sxx,Syy=,Szz,Tyz,Tzx,Txy, tension +=psi
-7721.0 -5774.0 -5906.0 0.0 0.0 0.0
Ramp Stress Sxx,Syy=,Szz,Tyz,Tzx,Txy, tension +=psi
-7721.0 -5774.0 -5906.0 0.0 0.0 0.0
0.0 0.0 0.0
No gravity stress is applied rather, the premining stress is
“additional” and based on formulas developed from many
in situ stress measurements (Board and Beus 1989).
A spiral ramp begins on a level grade and then begins
to decline according to the design grade in a circular path
for 360 deg or more as desired. Figure 7 shows the mesh
Figure 7. A cross-section of a spiral ramp with a design grade of 15 percent. The ramp is circular so sections are at 0, 180 and
360 deg are shown. The section is 11x11 ft (3.4x3.4 m). The spiral radius is 11.25 times opening width or 123.74 ft (37.7 m)