Mining-Induced Pressure-Relief Mechanism of Coal-Rock Mass for Different Protective Layer Mining Modes

Table 4

Gas parameters of no. 8, no. 9, and no. 10 coal seams in III1 mining area.

Seam	Gas pressure (MPa)	Gas content (m^3/t)	Adsorption constant		Coal hardness	Porosity (%)	Initial velocity of initial gas diffusion (mL/s)
			a (m^3/t)	b (MPa^−1)
Nos. 8 and 9	4.43–6.47	22.67–25.63	35.59–39.06	0.48–0.53	0.1–0.3	4.61	17–30
No. 10	2.7–5.3	13	15.25–29.83	0.41–1.3	0.8–1.13	6.87	7.6–8.9