Failure Mechanism of a Coal-Rock Combined Body with Inclinations of Structural Planes and a Calculation Model for Impact Energy

Table 1

Mechanical properties of coal and rock.

Material	Uniaxial compressive strength (MPa)	Shear strength (10^3 MPa)	Dynamic failure time (ms)	Elastic energy index	Impact energy index	Elastic modulus (10^3 MPa)	Poisson’s ratio
Coal	24.97	7.97	34	7.75	8.91	6.72	0.31
Rock	46.91	16.56	152	14.14	11.42	12.34	0.29