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

Table 2

Comparison of gas content test results after taking measures.

Test tunnel	Before and after the measures	Average W1 + W2	Average W	Average W3 m^3/t	Pressure MPa	Free gas	During coal cutting total amount of gas released from coal	( + )/
8006 air-return	Before	4.06	14.33	7.60	1.56	0.38	4.06	0.29
	After	2.61	12.14	7.17	1.02	0.25	2.61	0.21
8006 haulageway	Before	4.16	14.38	8.42	1.38	0.35	4.16	0.30
	After	3.08	12.90	7.44	1.10	0.28	3.08 < X < 3.36	0.24