A Study of Rockburst Hazard Evaluation Method in Coal Mine

Table 5

Characteristics of rockburst.

Number	Time	Energy of centrum /J	Accumulated energy /×10^6 J	Distance from rockburst to centrum /m	Characteristics of rockburst	Reason	Type of rockburst	RDE
1	Aug. 30, 2012		60	30	50 m in front of working face; roof-to-floor convergence of 0.6 m, rib sides convergence of 1.2 m	Accumulated energy releasing of coal pillar induced by first weighting of hard roof	Dynamic load type during mining face advancing	5.09
2	Jan. 9, 2013		60	40	40 m in front of working face; roof-to-floor convergence of 0.7 m, rib sides convergence of 0.5 m; working face supports broken	Accumulated energy releasing of coal pillar induced hard roof rupture	Dynamic load type	4.56
3	Feb. 1, 2013		30	50	Rib spalling of 2 m, many working face supports broken, and one day of production stop	Accumulated energy releasing of coal wall induced hard roof rupture	Dynamic load type	3.22
4	Mar. 15, 2013		30	40	40 m in front of working face; reduction rate of return airway section of 100%, four people dead, 30 days of production stop	Accumulated energy releasing of coal wall induced hard roof rupture	Dynamic load type	9.27
5	May 1, 2013		60	35	Reduction rate of return airway section of 60%	Accumulated energy releasing of coal pillar induced hard roof rupture	Dynamic load type	6.72