Research on Key Factors Influencing Surface Subsidence of Paste Backfilling Mining in Thick Coal Seam of Deep Mine

Table 6

Weight of evaluation indicators.

Criterion layer	Weight coefficient	Quantitative/primary qualitative indicators	Weight coefficient	Secondary qualitative indicators	Weight coefficient
Mining geological conditions	0.15	Mining depth	0.20	Original rock stress	0.54
				Tectonic stress	0.46
		Coal seam	0.21	Coal seam dip angle	0.48
				Coal seam thickness	0.52
		Surface water drainage	0.23
		Overburden structure	0.36	Strength of roadway	0.31
				Key layer location	0.34
				Topsoil thickness	0.35
Approach of roof and floor	0.28	Subsidence before filling	0.36	Roof subsidence	0.66
				Floor heave	0.27
				Stress expansion	0.07
		Nonbackfilling account	0.47
		Floating coal	0.12
		Rock compression	0.05
Filling body	0.32	Volume shrinkage	0.17	Bleeding rate	0.45
				Water content	0.55
		Volume compression	0.35	Bulk concentration	0.53
				Volumetric strain	0.47
		Strength of filling body	0.48	Poisson’s ratio	0.49
				Elastic modulus	0.51
Mining and filling technology	0.17	Mining technology	0.33	Mining speed	0.36
				Support mode	0.38
				Coal pillar strength	0.26
		Filling technology	0.47	Filling step	0.40
				Unsupported roof span	0.42
				Filling sequence	0.18
		Slicing height	0.20
Overburden retained voids	0.08	Mining method	0.38	Strip mining	0.67
				Longwall mining	0.33
		Stratigraphic structure	0.34
		Surface structure	0.28