Study of the Roof Deformation Characteristics of Roadway Excavation Face and Unsupported Roof Distance

Table 6

Mechanical parameters of coal and rock.

Name	Density (kg/m^3)	Cohesion (MPa)	Tensile strength (MPa)	Angle of internal friction (°)	Shear modulus (GPa)
Floor	2,350	1.15	1.23	33	0.216
Immediate roof	2,100	0.76	0.90	32	0.314
Coal seam	1,350	0.20	0.59	30	0.312
Main roof	2,550	1.34	1.44	34	0.226