Comprehensive Analysis of Stability of Coal Seam Composite Roof Based on Analytic Hierarchy Process

Table 7

Classification table based on the comprehensive influence coefficient of the composite roof structure.

Factor	Rank	Comprehensive strength coefficient	Strata characteristics	Bending strength (MPa)
qk	I	0.7 < k < 1	Stable	6.53–10.48
	II	0.4 < k < 0.7	Slightly stable	3.86–6.53
	III	0 < k < 0.4	Unstable	0.00–3.86