Highwall mining of thick, steeply dipping coal–a case study …
The following are the SFs and design criteria typically used in designing a highwall mining excavation area: A highwall mining panel should not exceed 20 openings between barrier pillars. Web pillar SF ≥ 1.6 for normal operations. Web pillar SF ≥ 2.0 for protection of critical structures. Minimum 0.8 web pillar width-to-height (w:h) ratio
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