Table 5 Statistics on the average count rate of acoustic emission at each loading stage of coal samples with different water immersion times.
Stage | Average AE count rate of coal samples (4 MPa)/(times s−1) | Average AE count rate of coal samples (8 MPa)/(times s−1) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
Dry | Immersion | Dry | Immersion | |||||||
1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | |||
Compaction stage | 52 | 5 | 4 | 2 | 3 | 74 | 7 | 14 | 6 | 3 |
Elastic stage | 246 | 28 | 38 | 24 | 21 | 290 | 66 | 46 | 54 | 40 |
Yield stage | 626 | 312 | 265 | 248 | 229 | 891 | 518 | 486 | 467 | 452 |
Failure stage | 692 | 394 | 356 | 332 | 319 | 982 | 658 | 631 | 615 | 606 |
