Table 5 Numerical modeling: particle fine-scale parameters.
From: Hydraulic horizontal slit-stress synergistic unloading fracturing in coal seams
Microscopic parameters | Argillaceous siltstone | No. 9 seam | Argillaceous siltstone | Limestone | Fine sandstone |
|---|---|---|---|---|---|
Minimum radius of particles/m | 0.06 | 0.06 | 0.06 | 0.06 | 0.06 |
Grain to diameter ratio (maximum particle size/minimum particle size) | 1.66 | 1.66 | 1.66 | 1.66 | 1.66 |
Density kg/m3 | 2500 | 1350 | 2500 | 2650 | 2873 |
Contact modulus between particles/GPa | 12 | 2 | 12 | 15 | 10 |
Particle stiffness ratio | 3 | 1.6 | 3 | 3 | 3 |
Effective modulus of bonding/GPa | 7 | 2 | 7 | 15 | 10 |
Contact stiffness ratio | 1.6 | 1.2 | 1.6 | 3 | 2 |
Frictional coefficient | 0.577 | 0.577 | 0.577 | 0.577 | 0.577 |
Parallel bonding radius factor | 5e-3 | 5e-3 | 5e-3 | 5e-3 | 5e-3 |
Parallel bonding normal strength/MPa | 22 | 8 | 22 | 45 | 12 |
Parallel bonding tangential strength/MPa | 25 | 8 | 25 | 60 | 30 |
