A New Method for Predicting Coal and Gas Outbursts

Table 5

Gas desorption index K₁ of drilling cuttings based on geological structure and precursor areas of outbursts.

Area	Failure type of the coal seam	K1max index	Geological structure	Outburst precursor
Return air roadway in the 121901 working face	III, IV	0.56	Thinning of coal seam	—
Return air roadway in the 121901 working face	III, IV	0.83	Thinning of coal seam	—
Return air roadway in the 121901 working face	III, IV	0.89	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.82	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.95	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.69	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.80	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.57	Thickening of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.83	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.70	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.85	Thinning of coal seam	—
Transportation roadway in the 121901 working face	III, IV	0.74	Thinning of coal seam	—
connection roadway in the 121901 working face	III, IV	1.01	Thinning of coal seam	—
connection roadway in the 121901 working face	III, IV	1.04	Thinning of coal seam	—
South return air roadway at 1800 m level	III, IV	0.72	Thinning of coal seam	Coal burst
Transportation roadway in the 121901 working face	III, IV	0.78	Thinning of coal seam	Emission after pulling the drill pipe out
connection roadway in the 121901 working face	III, IV	0.88	Thinning of coal seam	Emission after pulling the drill pipe out
connection roadway in the 121901 working face	III, IV	0.88	Thickening of coal seam	Emission after pulling the drill pipe out