Study on the Key Technology of Controlling the Instability of Deep High-Stress Coal and Rock Mass and Relieving the Danger

Table 1

Statistics of noise coal gun in the roadway.

Date	Frequency of sound	Frequent noise frequency	Sound frequency	Position
February 20th	12	8 o’clock	6	Middle of roof
February 21th	2	4 o’clock	1	Roof fracture
February 22th	2	8 o’clock	2	—
February 23th	13	8 o’clock	8	Wind tunnel gang
February 24th	15	8 o’clock	7	There are 4 air ducts and two pedestrians
February 25th	13	8 o’clock	9	Air duct, pedestrian, 10–15 m from head to back 10-15 m
February 26th	2	8 o’clock	9	—
February 27th	6	4 o’clock	—	—
February 28-29th	0	—	—	—