Verification of the New Coal Pillar Strength Formula and Investigations Into the Prediction of Pillar Life in Witbank and Highveld CoalfieldsMining, Underground Mining / Feb 1, 2004 Oct 8, 2019 by I Canbulat | February 2004 Task-2.13.1-Verification-of-the-new-coal-pillar-strength-formula-and-investigations-into-the-prediction-of-pillar-life-2004Download