Thickness of seam appears to be an important parameter (Tables 1-2). In these tables, FA and RA indicate the front and rear abutments, respectively. Subscripts u and I indicate the upper and lower seams, respectively. And the subscripts f and b indicate the face (right flank of the gob) and barrier (left flank of the gob), respectively. Thus, FA_(uf) indicates the front abutment on the face, in the upper seam; FA_(ib), the front abutment on the barrier, in the lower seam: and RA, the rear abutment (in the gob), in the upper seam.The peak value of s_1 on the face-rib, in the upper seam, decreases with the increase in the thickness of the seam. On the corresponding barrier-rib also, the value appears to decrease with the increase in the thickness of the seam. On the barrier-rib in the lower seam, the behaviour is same. On the corresponding face-rib, the behaviours is more pronounced. On the rear abutments, in the respective seams, the decrease in loading with the increase in the thickness of the seams continues.Peak loading zone on the face-rib in the upper seam, in the base problem, penetrates deeper into the coal at the roof level. Depth of penetration reduces as we move towards the floor. In case 3(t=10), while moving from the roof to the floor, the depth of penetration decreases up to a certain point, beyond which it is constant up to another point; beyond this point, it increases.The intensity and extent of relaxation, above and below the excavations, appears to decrease with the increase in the thickness of the seam.The trend of decrease in abutment loadings on face-ribs, barrier-ribs, as well as, rear abutments, with the increase in the thickness of seams, continues.
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