Analysis on Rock Burst Risks and Prevention of a 54 m-Wide Coal Pillar for Roadway Protection in a Fully Mechanized Top-Coal Caving Face

Table 1

Statistic of rock burst events.

Time	Location of seismic source	Seismic energy/J	Position of occurrence	Coverage of damages (m)
12:46, May 12	137 m in front of the working face and 38 m to the entity coal side of the intake airway	5.0 × 10^4	112–162 m on the advance face of the intake airway	50
21:44, May 19	129.5 m in front of the working face and 89 m to the entity coal side of the intake airway	5.4 × 10^3	15–70 m on the advance face of the intake airway	55
02:34, May 28	162 m behind the working face and 60 m to the entity coal side of the intake airway	5.8 × 10^4	24.6–52.6 m on the advance face of intake airway	28
20:59, May 31	88 m in front of the working face and 15 m to the entity coal side of the intake airway	7.8 × 10^4	0–50 m on the advance face of the intake airway	50
12:27, June 1	22 m behind the working face and intake airway	5.8 × 10^4	33–68 m on the advance face of the intake airway	36
1:22, June 5	13 m in front of the working face and 54 m to the mining area of the transportation roadway	4.4 × 10^5	6–54 m on the advance face of the intake airway	48
10:10, June 13	90 m behind the working face and 265 m to the mining area of the intake airway	3.8 × 10^5	80–103 m on the advance face of the intake airway	23
23:15, June 17	67 m in front of the working face and 60 m to the mining area of the intake airway	1.7 × 10^4	80–100 m on the advance face of the intake airway	20