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

Table 23

Detailed parameters of the main inclined shaft.

	Parameter	Value	Dimension
Parameters of the surrounding rock	Cohesion	0.76	MPa
	Internal friction angle	17	（o）
Section size	Width	6400	mm
	Height	4400	mm
Bolt support parameter	Length	2400	mm
	Strength	335	MPa
	Diameter	22	mm
	Column spacing	800	mm
	Row spacing	900	mm