ABSTRACT
Based on intense field study in India a very simple but realistic mathematical model developed by the author to determine the optimum capacity of the powered roof supports for the longwall faces. 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 Top seam of a mine belongs to the Pranhita-Godavari valley coal-field of India. The calculated capacity of the powered roof supports for the Top seam is 555 tonne or 610 tonne depending upon the type of chock-shield supports are selected. However the 610tonne capacity chock-shield support as shown in the Fig. 3 would be the right choice for the fore going mentioned Top coal seam.
