ABSTRACT
After analyzing roof strata behavior logically and elaborately around various longwall panels in India, a new strata mechanics concepts developed. Based on this strata mechanics concepts a very simple but realistic mathematical model developed to determine the optimum capacity of the powered roof supports. This concept considered the combined loads offered by the detachment of strata layers/composite layer blocks right from the face and also loads due to the defection by the strata layer/composite layers situated above the detached roof rock-mass. This formula along with the other associated formulae by the author prompted to determine the optimum capacity requirement of the powered supports to be used in the king seam of a mine belongs to the Pranhita-Godavari valley coal-field of India. The calculated capacity of the powered roof supports for the king seam is 761 tonne or 836 tonne depending upon the type of chock-shield supports are to be selected. However the 836 tonne capacity chock-shield support would be the right choice for the foregoing mentioned king coal seam.
