A Novel Coal Burst Criterion of Anchored Roadway Surrounding Rock under Dynamic Disturbance

Table 1

Hazard degree classification for coal burst of roadway.

Degree	No hazard	Weak hazard	Moderate hazard	Strong hazard
Hazard index δ	0 < δ < 0.25	0.25 ≤ δ < 0.50	0.5 ≤ δ < 0.75	0.75 ≤ δ < 1