2
to mitigate stress concentration and maintain gateroad
stability.
In response to these challenges, a proposed 3-Entry lay-
out introduces a Y-Y pillar arrangement with a wider 320-ft
(C-C) inter-panel barrier with 50 ft by 160 ft (C-C) yield
pillars (see Figure 3).
This new design aims to improve stability by distrib-
uting stress more evenly across the barrier pillar, thereby
reducing loading conditions that contribute to floor insta-
bility in the current layout. This proposed design is expected
to reduce floor heave in the 1,000-ft panel configuration by
optimizing pillar placement and function.
METHODOLOGY
This study evaluates the stress distributions and pillar per-
formance under two critical scenarios: first, the stress pro-
files measured across the gateroad following the completion
of the first panel, and second, the stress profiles observed
across the pillars isolated between two gobs after mining
the second panel. Additionally, the analysis includes evalu-
ating pillar safety factors to better understand the pillars’
stability under varying stress conditions. By comparing
these two critical stress environments, this study aims to
identify stress redistribution patterns and assess the pillar
layouts’ effectiveness in maintaining gateroad stability.
The primary tool used for this analysis is the LaModel
program, which allows for a detailed examination of stress
profiles and safety factors under different pillar layouts.
Each pillar configuration is evaluated regarding stress dis-
tribution and pillar safety. The insights gained from this
evaluation are intended to inform future improvements to
pillar design in deep-cover longwall mining operations.
Figure 1. Plan view of mine map depicting the previously
used four-entry yield-abutment-yield pillar layout
Figure 2. Plan view of mine map depicting the currently used
three-entry yield-abutment pillar layout with an inter-panel
barrier
Figure 3. Plan view of mine map depicting the proposed
three-entry yield-yield pillar layout with wider inter-panel
barrier
to mitigate stress concentration and maintain gateroad
stability.
In response to these challenges, a proposed 3-Entry lay-
out introduces a Y-Y pillar arrangement with a wider 320-ft
(C-C) inter-panel barrier with 50 ft by 160 ft (C-C) yield
pillars (see Figure 3).
This new design aims to improve stability by distrib-
uting stress more evenly across the barrier pillar, thereby
reducing loading conditions that contribute to floor insta-
bility in the current layout. This proposed design is expected
to reduce floor heave in the 1,000-ft panel configuration by
optimizing pillar placement and function.
METHODOLOGY
This study evaluates the stress distributions and pillar per-
formance under two critical scenarios: first, the stress pro-
files measured across the gateroad following the completion
of the first panel, and second, the stress profiles observed
across the pillars isolated between two gobs after mining
the second panel. Additionally, the analysis includes evalu-
ating pillar safety factors to better understand the pillars’
stability under varying stress conditions. By comparing
these two critical stress environments, this study aims to
identify stress redistribution patterns and assess the pillar
layouts’ effectiveness in maintaining gateroad stability.
The primary tool used for this analysis is the LaModel
program, which allows for a detailed examination of stress
profiles and safety factors under different pillar layouts.
Each pillar configuration is evaluated regarding stress dis-
tribution and pillar safety. The insights gained from this
evaluation are intended to inform future improvements to
pillar design in deep-cover longwall mining operations.
Figure 1. Plan view of mine map depicting the previously
used four-entry yield-abutment-yield pillar layout
Figure 2. Plan view of mine map depicting the currently used
three-entry yield-abutment pillar layout with an inter-panel
barrier
Figure 3. Plan view of mine map depicting the proposed
three-entry yield-yield pillar layout with wider inter-panel
barrier