Mechanism of Coal Seam Permeability Enhancement and Gas Outburst Prevention under Hydraulic Fracturing Technology

Table 1

Basic physical and mechanical parameters of coal and rock.

Compressive strength/MPa	Tensile strength/MPa	Elastic modulus/GPa	Poisson’s ratio	Internal friction angle/(°)	Friction coefficient	Density/(kg/m^3)
10.12	2.18	2.49	0.28	35.22	0.734	1289