4
strength, which would be influenced by pillar size in strain-
softening materials.
STRESS ANALYSIS
The chart below illustrates the vertical stress profiles across
the gateroads after completing the first-panel mining. This
analysis compares three gateroad pillar configurations:
the previously implemented 4-Entry layout, the current
3-Entry Y-A configuration, and the proposed 3-Entry Y-Y
layout (see Figure 6).
The stress profiles capture the total vertical stress expe-
rienced at each element across the gateroads. As expected,
the vertical stresses are the highest closer to the gob edge.
The proposed 3-Entry Y-Y layout, for example, shows the
highest peak stress adjacent to the gob of the active panel.
However, this stress dissipates across the large barrier result-
ing in reduced stress levels as the unmined adjacent panel is
approached compared to the 4-Entry and 3-Entry Y-A lay-
outs. This reduction is most notable in the tailgate region
of the subsequent panel, where managing ground stability
is critical. These findings suggest that the 3-Entry Y-Y lay-
out has the potential to redistribute stress more effectively,
reducing concentrations and improving overall stability
within the gateroad.
Analyzing the barrier pillar stability for the 4-Entry,
3-Entry Y-A, and 3-Entry Y-Y configurations, the stress
distribution across the abutment/barrier pillar was closely
compared. The 4-Entry scenario had the highest average
stress of 5,988 psi. The 3-Entry Y-A scenario showed an
average stress of 5,110 psi, while the 3-Entry Y-Y scenario
demonstrated the lowest average stress of 4,878 psi. The
3-Entry Y-Y scenario provides approximately a 19% reduc-
tion in the average stress compared to the 4-Entry scenario
and a 5% reduction in the average stress compared to the
3-Entry Y-A scenario. The reduction is particularly notable
near the adjacent tailgate entries on the far side of the bar-
rier, where the 3-Entry Y-Y configuration is intended to
redistribute stress more evenly across the pillars. In the #3
entry, adjacent to the barrier, a stress reduction of approxi-
mately 17% was observed compared to the 4-Entry sce-
nario and 11% for the 3-Entry Y-A scenario. This indicates
the potential for the Y-Y layout to improve stability and
mitigate stress-induced floor instability.
Building on the findings from the initial analysis of the
first-panel mining, further investigation was conducted to
assess the stress profiles across the barrier or abutment pil-
lar in the 4-Entry scenario, isolated between gobs after the
second-panel mining. This detailed examination clarifies
the maximum loading conditions these pillars are expected
to resist (see Figure 7).
Based on the LaModel simulation, the average stress
values for the 4-Entry, 3-Entry Y-A, and 3-Entry Y-Y sce-
narios were 9,038 psi, 7,640 psi, and 7,050 psi, respectively.
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
-100 0 100 200 300 400 500 600 700
X-Location Along Cross Section (ft)
Total Vertical Stress Profile Across Gateroad Pillars -First Panel
4-Entry
3-Entry Y-A
3-Entry Y-Y
Figure 6. Stress profiles across the gateroad pillars after first-panel mining for the three scenarios
Total
Verti
l
Stress
(psi)
strength, which would be influenced by pillar size in strain-
softening materials.
STRESS ANALYSIS
The chart below illustrates the vertical stress profiles across
the gateroads after completing the first-panel mining. This
analysis compares three gateroad pillar configurations:
the previously implemented 4-Entry layout, the current
3-Entry Y-A configuration, and the proposed 3-Entry Y-Y
layout (see Figure 6).
The stress profiles capture the total vertical stress expe-
rienced at each element across the gateroads. As expected,
the vertical stresses are the highest closer to the gob edge.
The proposed 3-Entry Y-Y layout, for example, shows the
highest peak stress adjacent to the gob of the active panel.
However, this stress dissipates across the large barrier result-
ing in reduced stress levels as the unmined adjacent panel is
approached compared to the 4-Entry and 3-Entry Y-A lay-
outs. This reduction is most notable in the tailgate region
of the subsequent panel, where managing ground stability
is critical. These findings suggest that the 3-Entry Y-Y lay-
out has the potential to redistribute stress more effectively,
reducing concentrations and improving overall stability
within the gateroad.
Analyzing the barrier pillar stability for the 4-Entry,
3-Entry Y-A, and 3-Entry Y-Y configurations, the stress
distribution across the abutment/barrier pillar was closely
compared. The 4-Entry scenario had the highest average
stress of 5,988 psi. The 3-Entry Y-A scenario showed an
average stress of 5,110 psi, while the 3-Entry Y-Y scenario
demonstrated the lowest average stress of 4,878 psi. The
3-Entry Y-Y scenario provides approximately a 19% reduc-
tion in the average stress compared to the 4-Entry scenario
and a 5% reduction in the average stress compared to the
3-Entry Y-A scenario. The reduction is particularly notable
near the adjacent tailgate entries on the far side of the bar-
rier, where the 3-Entry Y-Y configuration is intended to
redistribute stress more evenly across the pillars. In the #3
entry, adjacent to the barrier, a stress reduction of approxi-
mately 17% was observed compared to the 4-Entry sce-
nario and 11% for the 3-Entry Y-A scenario. This indicates
the potential for the Y-Y layout to improve stability and
mitigate stress-induced floor instability.
Building on the findings from the initial analysis of the
first-panel mining, further investigation was conducted to
assess the stress profiles across the barrier or abutment pil-
lar in the 4-Entry scenario, isolated between gobs after the
second-panel mining. This detailed examination clarifies
the maximum loading conditions these pillars are expected
to resist (see Figure 7).
Based on the LaModel simulation, the average stress
values for the 4-Entry, 3-Entry Y-A, and 3-Entry Y-Y sce-
narios were 9,038 psi, 7,640 psi, and 7,050 psi, respectively.
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
-100 0 100 200 300 400 500 600 700
X-Location Along Cross Section (ft)
Total Vertical Stress Profile Across Gateroad Pillars -First Panel
4-Entry
3-Entry Y-A
3-Entry Y-Y
Figure 6. Stress profiles across the gateroad pillars after first-panel mining for the three scenarios
Total
Verti
l
Stress
(psi)