A Study of Safety Coefficient Determination and Support Parameter Optimization Based on Vulnerability Preevaluation

Table 20

The weights of the evaluation indexes.

Layer-1	Weight	Layer-2	Weight	Layer-3	Weight
Characteristics of the surrounding rock	0.31	Surrounding rock integrity	0.35
		Strength of the surrounding rock	0.35	Roof	0.35
				Rib	0.4
				Floor	0.25
		Roof rock types	0.1
		Gateway type	0.1
		Dip angle of the surrounding rock	0.1
Stress condition	0.4	Section parameter	0.1	Section type	0.5
				Section size	0.5
		Construction disturbance	0.35	Degree	0.5
				Time	0.5
		Geological structure	0.3
		Buried depth	0.1
		Major horizontal principal stress	0.15	Value	0.4
				Angle	0.6
Geological environment	0.1	Underground water	0.5
		Underground temperature	0.5
Service condition	0.19	Inspection and maintenance	0.2
		Service time	0.8