ICGCM Papers:
Analytical and Numerical Modeling Studies
 
 
The Ground Response Curve, Pillar Loading and Pillar Failure in Coal Mines
29th International Conference on Ground Control in Mining
The Ground Response Curve, Pillar Loading and Pillar Failure in Coal Mines
by
Essie EsterhuizenChris MarkMichael M. Murphy, NIOSH, Office of Mine Safety and Health Research, Pittsburgh, United States
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[Conference] 29th International Conference on Ground Control in Mining
[Price] Free  [Comments] 1
[Topical Area] Analytical and Numerical Modeling Studies
[Author] Essie EsterhuizenChris MarkMichael M. Murphy, NIOSH, Office of Mine Safety and Health Research, Pittsburgh, United States
[Abstract] 

This paper builds on results presented in a paper titled "Numerical Model Calibration for Simulating Coal Pillars, Gob and Overburden Response" by introducing the concept of the ground response curve and how it can be used to explain load distribution around coal mine panels.  The work was carried out as part of the NIOSH study of retreat pillar mining at depth that was carried out during 2008 and 2009.  

 

The FLAC3D stress analysis package was used to model various overburden types varying from the typical low strength eastern mines to higher strength western mines.  The study made use of calibrated pillar, gob and overburden models to investigate how the pillar response and the overburden response are linked.  The initial yield of the coal around the perimeter of a pillar is shown to have a significant impact on the final pillar stress because it influences the intersection point of the ground response curve and the pillar stress-strain curve.  The influence of overburden stiffness on ultimate pillar loads will be shown.  The impact of geological composition of the overburden and mining geometry on the ground response curve are also discussed in this paper.

 

A series of conceptual retreat mining panels are simulated and the pillar strain and stress at equilibrium are compared to the predicted stability factors from the NIOSH Analysis of Pillar Stability (ALPS) pillar design program to demonstrate how the ground response curve impacts the ultimate stability condition of the pillars in a panel.  The concept of pillar strain as a potential indicator of acceptable pillar conditions is addressed in this paper.