Verification of the New Coal Pillar Strength Formula and Investigations Into the Prediction of Pillar Life in Witbank and Highveld Coalfields
Covers pillar load and strength estimation, the limits of tributary area theory, and the extraction gains available from revised strength formulae, for rock engineers designing bord and pillar workings.
by I Canbulat | February 2004
Laboratory testing showed coal specimen strength rising linearly with width to height ratio and falling exponentially with specimen size, the size effect becoming insignificant beyond about 2 m diameter. The slope of that relationship was the same for coals from different mines, while the intercept varied with specimen size.
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