ICGCM Papers:
Analytical and Numerical Modeling Studies
 
 
A Comparison of the Overburden Loading in ARMPS and LaModel
29th International Conference on Ground Control in Mining
A Comparison of the Overburden Loading in ARMPS and LaModel
by
Ihsan Berk TuluKeith A Heasley, West Virginia University, Morgantown, United StatesChris Mark, 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] 0
[Topical Area] Analytical and Numerical Modeling Studies
[Author] Ihsan Berk TuluKeith A Heasley, West Virginia University, Morgantown, United StatesChris Mark, NIOSH, Office of Mine Safety and Health Research, Pittsburgh, United States
[Abstract] 
A Comparison of the Overburden Loading
in ARMPS and LaModel
 
By
 
Ihsan Berk Tulu, Keith A. Heasley and Chris Mark
 

The Analysis of Retreat Mining Pillar Stability (ARMPS) and the LaModel program have been used successfully in the U.S. for designing safe pillar recovery operations for many years.  However, the recent Crandall Canyon Mine collapse showed that further research is required to improve the design of the pillar recovery under deep cover.  In this regard, the National Institute for Occupational Health and Safety (NIOSH) and West Virginia University (WVU) Mining Engineering Department have been working together to improve both the ARMPS and the LaModel programs.

      In this research, the distribution of overburden load between: the retreat line pillars, the gob, and the barrier pillars in both programs has been extensively studied. In the original ARMPS, the overburden load was distributed using: the tributary area theory for development, the abutment angle concept for gob loading, and an empirical curve for abutment loading. More recently, scientists from NIOSH have implemented an improved method of calculating the gob loading in ARMPS using a pressure arch concept. In LaModel, the overburden load distribution is determined by the bending stiffness of the laminated overburden and the relative stiffness (and failure strength) of the: pillars, gob and barriers. With free user input, the overburden load distribution in LaModel could vary widely. However, the new LaModel calibration procedure for deep cover retreat mining dictates a specific method of determining input parameters and therefore essentially dictates a specific overburden load distribution.
      In this paper, the overburden loads calculated by ARMPS (using both the abutment angle and the pressure arch concept) and LaModel (using the recommended calibration method) on: the retreat line pillars, the gob and the barrier pillars are analyzed and compared.   This analysis shows a number of distinct differences between the ARMPS and LaModel load distributions. Ultimately, the two programs with their distinctive load distributions are used to analyze a database of 47 deep cover pillar retreat case studies and the ability of each program to discriminate successful from unsuccessful retreat pillar plans is determined.