Stability Analysis and Control Measures of Large-Span Open-Off Cut with Argillaceous Cemented Sandstone Layered Roof

Table 1

The mechanical parameters of coal and rock.

Mineral	Bulk density (kg/m^3)	Shear modulus (GPa)	Bulk modulus (GPa)	Cohesion (MPa)	Friction angle (°)	Tensile strength (MPa)
Medium sandstone	2560	0.47	0.62	1.20	28	0.50
Fine sandstone	2600	0.46	0.61	1.10	28	0.46
Fine and medium sandstone	2560	0.44	0.59	1.10	27	0.45
Fine, silty and muddy sand strata	2550	0.41	0.68	1.05	27	0.43
31 upper coal seam	2400	0.37	0.79	0.85	26	0.34
Siltstone	2450	0.42	0.71	1.10	27	0.45
Siltstone, fine sandstone	2560	0.44	0.59	1.10	27	0.45
Fine sandstone	2600	0.46	0.61	1.20	28	0.50