Gas Expansion Energy Model and Numerical Simulation of Outburst Coal Seam under Multifield Coupling

Table 1

The physical parameters.

Parameters and units	Value
Elasticity modulus of coal /(GPa)	3
Elasticity modulus of coal matrix /(GPa)	8
Poisson’s ratio of coal	0.32
Density of coal /(kg/m^3)	1350
Elasticity modulus of coal /(GPa)	30
Poisson’s ratio of rock	0.2
Density of rock /(kg/m^3)	2450
Cohesion of coal /(MPa)	1.45
Friction angle of coal /(°)	30
Langmuir pressure constant of coal /(MPa)	1
Langmuir constant volume of coal (m^3/kg)	0.02
Initial matrix porosity of coal	0.03
Initial fracture porosity of coal	0.001
Initial permeability (m^2)	1e-13
Gas dynamic viscosity /(Pa·s)	1.52e-5
Initial diffusion coefficient /(m^2/s)	5e-11