Numerical Investigation of Influences of Drilling Arrangements on the Mechanical Behavior and Energy Evolution of Coal Models

Table 2

Microparameters used in the PFC2D model.

Microparameters	Values
Elastic modulus of the particle, Ec (GPa)	0.45
Parallel-bond radius multiplier	1.0
Ratio of normal to shear stiffness of the particle, kn/ks	2.5
Ratio of normal to shear stiffness of the parallel bond,	2.5
Particle friction coefficient,	0.5
Parallel-bond normal strength, σn (MPa)	8.75
Parallel-bond shear strength, τn (MPa)	10.5