Numerical analysis of displacement and pressure distribution around a longwall panel in steep coal seam

Document Type : research - paper

Authors

1 shahrood university tech.

2 -

Abstract

Pressure distribution and estimation methods of cover pressure distance in the goaf of longwall coal mines has always been challenging due to the inaccessibility of the waste area. When a longwall panel is excavated, the overburden strata are disturbed in order of severity from the immediate roof towards the surface. The immediate roof behind the longwall face collapses at a distance that changes depending on the properties of rock, the thickness of immediate strata, and on the type and nature of strata. To date, extensive attempts have been made for a comprehensive understanding of the stress and deformation state of the caved and fracture zone in horizontal working faces but research has been rare on steep coal seams. In the present study, stress and displacement redistribution and cover pressure distance in the longwall steep coal mines was analyzed by using the finite difference method and the result was compared with existing literature available. In general, displacement and stress redistribution template is in accordance with the previous research works. Depth, excavation height, bulking factor and compressive strength of the rock fragments is affecting cover pressure distance. Cover pressure distance was determined 198 m and it shows a close agreement with the literature. Support system evaluation was made by Sakurai’s critical strain for underground excavations and tunnels and so the stope’s lower part and the conveyance roadway were determined as critical locations.

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References

7- منابع

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Journal of Mining Engineering
Volume 14, Issue 42
June 2019
Pages 17-31

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History

  • Receive Date: 09 May 2018
  • Revise Date: 09 June 2018
  • Accept Date: 20 June 2018

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