Numerical Study of Damage to Rock Surrounding an Underground Coal Roadway Excavation

Table 1

Calculated macrostrength parameters of intact rock and rock mass.

Lithology	Intact rock		RQD	Rock mass
	Er (GPa)	UCSr (MPa)		Em (GPa)	UCSm (MPa)
Fine sandstone	4.6	41.37	65.50	0.94	13.57
Siltstone (roof)	3.4	36.50	56.87	0.48	9.24
Mudstone (roof)	1.8	15.30	42.72	0.14	2.53
4-2 coal	2.4	10.30	36.06	0.14	1.40
Mudstone (floor)	1.8	15.30	42.72	0.14	2.53
Siltstone (floor)	3.4	36.80	57.00	0.48	9.35