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Experimental Evaluation of a Two-Entry Gate-Road Yield Pillar: Convergence Monitoring and Physical Properties

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Gate-road yield pillars are subject to increases in stress as the longwall face advances toward the pillars. Increases in pillar stress can be inferred by measuring roof/floor convergence surrounding the pillar. This paper presents a case study of convergence measurements surrounding a two-entry gate-road yield pillar in the head gate of a coal mine. Convergence was measured over a six-month period, as the longwall face approached and passed the pillar. Measurements were collected at eight locations surrounding the pillar: four locations in the travelway and four locations in the beltway. In addition to convergence stations, the pillar was instrumented with an array of seismometers. In future analysis, convergence measurements will be compared to seismic interpretations. This study reports on the geology and geometry of the longwall panel, the roof and rib support, the change in convergence over time, and the physical properties of coal and parting. Additionally, the convergence measurements are compared to pillar safety factor distributions derived from a finite element model. The convergence measurements contribute to the knowledge of when yield pillar abutment loading, caused by the encroaching longwall, is first detected. Knowing when abutment loading begins to yield the pillars can help define when standing secondary roof supports are required for head gate entry support.

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  1. 1.

    Esterhuizen GS, Gearhart DF, Klemetti T, Dougherty H, van Dyke M (2018) Analysis of gateroad stability at two longwall mines based on field monitoring results and numerical model analysis. Int J Min Sci Technol 29(1):35–43. https://doi.org/10.1016/j.ijmst.2018.11.021

  2. 2.

    Gearhart D, Esterhuizen G, Zhang P (2018) The effects of a passing Longwall face on the roadway, pillar, and standing supports in northern West Virginia. In: Mishra B, Klemetti T, Lawson H, Murphy M, Perry K (eds) Proceedings of the 37th international conference on ground control in mining. SME, Denver, pp 359–365

  3. 3.

    Doelling HH (1972) Central Utah Coal Fields: Sevier-Sanpete, Wasatch Plateau, Book Cliffs and Emery, Monograph Series No. 3. Utah Geological and Mineralogical Survey, Salt Lake City, Utah

  4. 4.

    Pariseau WG, McCarter MK, Wempen JM (2019) Comparison of closure measurements with finite element model results in an underground coal mine in Central Utah. Int J Min Sci Technol 29(1):9–15. https://doi.org/10.1016/j.ijmst.2018.11.013

  5. 5.

    Pariseau WG (2012) Design analysis in rock mechanics, 2nd edn. CRC Press, Taylor & Francis Group, London, pp 607–610

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Funding for this research was provided by the National Institute for Occupational Health and Safety. The conclusions of this work are those of the authors and do not necessarily represent the opinions or policies of the National Institute for Occupational Health and Safety.

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Correspondence to Dallan J. Coons.

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Coons, D.J., McCarter, M.K., Wempen, J.M. et al. Experimental Evaluation of a Two-Entry Gate-Road Yield Pillar: Convergence Monitoring and Physical Properties. Mining, Metallurgy & Exploration (2020). https://doi.org/10.1007/s42461-020-00192-y

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  • Longwall mining
  • Coal
  • Ground control
  • Convergence