Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Operating parameters of a powered roof support_
| Unit number | Fig. 5 | Fig. 6 | ||||||
|---|---|---|---|---|---|---|---|---|
| Control system | Shield arrangement with respect to the longwall face | Cutting depth z [m] | Rate of face advance [m/day] | Control system | Shield arrangement with respect to the longwall face | Cutting depth z [m] | Rate of face advance [m/day] | |
| 8 | Manual | Linear | 0.06 | 16.00 | Automatic | Saw tooth | 0.03 | 20.00 |
| 25 | Manual | Linear | 0.05 | Manual | Linear | 0.05 | ||
| 70 | Automatic | Saw tooth | 0.04 | Automatic | Saw tooth | 0.1 | ||
| 115 | Manual | Linear | 0.05 | Automatic | Saw tooth | 0.15 | ||
| 134 | Manual | Linear | 0.05 | Automatic | Saw tooth | 0.04 | ||
Statistical significance of model parameters_
| Effect | Parameter evaluation: z sigma parameterisation with constraints | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Acceptance condition: pmin≥24 MPa, pmax≤42 MPa, tp≤30 min | ||||||||||
| Leg pressure factor | Leg pressure, Standard error | Leg pressure, t-value | Leg pressure, p-value | -95,00% Confide. Interval | +95,00% Confide. Interval | Leg pressure, Beta (β) | Leg pressure, Error beta (β) | -95,00% Confide. Interval | +95,00% Confide. Interval | |
| Free term | 24.61 | 0.12 | 195.92 | 0.00 | 24.37 | 24.86 | ||||
| Roof barring factor | 6.75 | 0.09 | 77.65 | 0.00 | 6.58 | 6.92 | 0.31 | 0.004 | 0.30 | 0.32 |
| Rate of face advance factor | 0.02 | 0.003 | 5.89 | 0.00 | 0.01 | 0.02 | 0.02 | 0.01 | 0.01 | 0.02 |
| Compressive strength of roof strata factor | -0.06 | 0.01 | -18.91 | 0.00 | -0.06 | -0.05 | -0.06 | 0.01 | -0.07 | -0.06 |
| Standstill time of a support unit factor | 0.09 | 0.01 | 69.92 | 0.00 | 0.09 | 0.09 | 0.28 | 0.01 | 0.27 | 0.28 |
| Parameter evaluation: z sigma parameterisation with constraints | ||||||||||
| Acceptance condition:: pmin≥24 MPa, pmax≤42 MPa, tp≤60 min | ||||||||||
| Free term | 25.13 | 0.11 | 213.21 | 0.00 | 24.90 | 25.36 | ||||
| Roof barring factor | 7.07 | 0.07 | 93.72 | 0.00 | 6.92 | 7.21 | 0.31 | 0.01 | 0.30 | 0.32 |
| Rate of face advance factor | 0.01 | 0.01 | 5.59 | 0.00 | 0.01 | 0.02 | 0.01 | 0.01 | 0.01 | 0.02 |
| Compressive strength of roof strata factor | -0.07 | 0.01 | -25.44 | 0.00 | -0.08 | -0.07 | -0.08 | 0.01 | -0.08 | -0.07 |
| Standstill time of a support unit factor | 0.07 | 0.00 | 103.10 | 0.00 | 0.07 | 0.07 | 0.34 | 0.01 | 0.34 | 0.35 |
| Parameter evaluation: z sigma parameterisation with constraints | ||||||||||
| Acceptance condition:: pmin≥24 MPa, pmax≤42 MPa, tp≤250 min | ||||||||||
| Free term | 24.79 | 2.89 | 8.56 | 0.00 | 19.08 | 30.51 | ||||
| Roof barring factor | -0.09 | 3.23 | -0.03 | 0.97 | -6.48 | 6.28 | -0.01 | 0.07 | -0.14 | 0.14 |
| Rate of face advance factor | 0.28 | 0.05 | 4.98 | 0.00 | 0.17 | 0.39 | 0.35 | 0.07 | 0.21 | 0.48 |
| Compressive strength of roof strata factor | 0.11 | 0.06 | 1.69 | 0.09 | -0.02 | 0.23 | 0.12 | 0.07 | -0.02 | 0.27 |
| Standstill time of a support unit factor | 0.02 | 0.01 | 4.21 | 0.00 | 0.01 | 0.03 | 0.32 | 0.07 | 0.17 | 0.47 |
Operating parameters of powered roof support (shield) sections_
| Parameters | Value | Unit | |
|---|---|---|---|
| Shield height range | 0.95–2.0 | m | |
| Operating range | 1.0–1.9 | m | |
| Admissible inclination | Longitudinal | do 15° | - |
| Lateral | ± 15° | - | |
| Pitch | 1.75 | m | |
| Step | to 0.85 | m | |
| Number of legs | 2 | pcs. | |
| Leg diameter | Ø320 | mm | |
| Bearing capacity of the leg | Set (32 MPa) | 2.573 | MN |
| Yield (45 MPa) | 3.619 | MN | |
| Canopy | 4,030 | mm | |
| Yield pressure | 45 | MPa | |
| Supply pressure | 32 | MPa |