Mining Engineering > GATE 2017 > Underground Coal Mining
A bord and pillar panel is being planned at a depth of 300 m. The dimension of square pillar is 35 m centre-to-centre. The average unit weight of the overburden rock is 25 kN/m3. If the strength of the pillar is 14.0 MPa, the gallery width in m for a safety factor of 1.3 is _____________.
Correct : 5.5 to 6.0
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