Numerical Investigation on Influential Factors for Quality of Smooth Blasting in Rock Tunnels

Table 2

Factors and levels for the orthogonal design.

Level	Factors
	Perimeter hole spacing E (cm)	Least resistance line (cm)	Charge concentration H = E/	Charging explosive D (kg/m)	Type of rock mass T	Detonation velocity (m/s)	Drilling deviation M
1	50	55	0.93	0.15	III	3200	Qualified (1)
2	60	60	1	0.25	IV	5200	Poor (2)
3	70	65	1.07	0.35	—	—	—
4	80	70	1.14	0.45	—	—	—