Identification of Initial Crack and Fracture Development Monitoring under Uniaxial Compression of Coal with High Bump Proneness

Table 1

Average physical and mechanical parameters of the coals.

Density (kg/m^3)	Compressive strength (MPa)	Tensile strength (MPa)	Cohesion (MPa)	Internal friction angle (°)	Elastic modulus (GPa)	Poisson ratio
1350	30.00	3.89	5.16	29.27	4.62	0.32