Mining Engineering > GATE 2024 > Underground Coal Mining
A Bord and Pillar panel is developed at a depth of 250 m in a flat coal seam. The vertical stress gradient is 0.027 MPa/m. If the strength of a square pillar is 12.5 MPa, the extraction ratio of the pillar for a safety factor of 1.5, is ________.(round off up to 2 decimals)

Correct : 0.53

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Related Topics

Bord and pillar panel mining GATE Mining Engineering 2024 vertical stress gradient coal seam square pillar strength extraction ratio mining mining engineering gate safety factor extraction coal seam mining engineering GATE 2024 question 32

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