Hierarchic Analysis Method to Evaluate Rock Burst Risk

Table 1

Magnitude strength and throw coal method of rock burst evaluation.

Magnitude strength	Weight of thrown coal/t	Risk level
<1	5	Micro shock (level I)
<1	5–10	Weak shock (level II)
1-2	10–50	Medium impact (level III)
>2	>50	Shock (level IV)