Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams

Table 1

Mechanical properties of the No. 9-15 coal.

Lithology	(MPa)	(MPa)	(GPa)		(MPa)	(°)
9-15 coal upper	39.06	1.96	3.84	0.26	3.8	40
9-15 coal middle	35.44	2.04	3.79	0.21	4.4	41
9-15 coal lower	31.56	1.91	2.32	0.23	3.9	42
Average	35.35	1.97	3.29	0.23	4.03	41