ICGCM Papers:
Pillar and Mine Design
 
 
Investigation of Pillar Loading Considerations in Determination of Pillar Stability Factors for Longwall Gateroad Design
32nd International Conference on Ground Control in Mining
Investigation of Pillar Loading Considerations in Determination of Pillar Stability Factors for Longwall Gateroad Design
by
Heather E LawsonJeffrey Whyatt, NIOSH, Office of Mine Safety and Health Research, Spokane, United StatesMark K Larson, CDC/NIOSH, Spokane Mining Research Division, Spokane, United States
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[Conference] 32nd International Conference on Ground Control in Mining
[Price] Free  [Comments] 0
[Topical Area] Pillar and Mine Design
[Author] Heather E LawsonJeffrey Whyatt, NIOSH, Office of Mine Safety and Health Research, Spokane, United StatesMark K Larson, CDC/NIOSH, Spokane Mining Research Division, Spokane, United States
[Abstract] 
Key Conclusions:
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The results of these studies indicate a need for further research in the implementation of a more robust pillar loading model that can better reflect the local ground characteristics and provide an opportunity to improve the empirical assessment of pillar design using the ALPS approach for a local or regional data base .
Key Findings:
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This study found that the abutment angle is particularly important for panels with supercritical geometries. As panels reach a subcritical geometry with increasing depth, the primary influence of the abutment angle is reduced and matched by other factors, including load transfer distance for tailgate loading, which is contradictory to the current ALPS assumptions.
Objective of the Paper:
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To investigate localized issues surrounding pillar loading.
Problem Statement:
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The current ALPS design software defines the critical pillar stability factor for assessing longwall gateroad performance based on a national database of case histories. This method has become the standard for longwall pillar designs in the United States. However, several regions of the United States use other methods to design their gateroad pillars. Vandergrift and Conover (2010) presented a successful design for a deep western mine that utilized significantly lower stability factors than recommended by ALPS. They developed a local mine experience database to justify the use of a lower pillar stability factor, which follows the alternate method proposed by Mark (1992). Recent field data providing measured pillar loading from a deep western mine supports an increased abutment extent compared to the ALPS assumptions (Lawson et al., 2012), which would produce less pillar loading and a higher pillar stability factor . To investigate the issues surrounding pillar loading in deep western mines, a parametric study of the ALPS input variables in conjunction with numerical modeling using the LaModel analysis software were performed.