Table 2 Observation Data of Pre-mining Borehole SD1 (As of April 30, 2019).
From: Surface damage reduction effect of ultra-high working face in Shangwan coal mine
Measuring point | Lithologic | Depth (m) | Distance from the top of coal seam (m) | Relative displacement (m) | Absolute displacement (m) |
|---|---|---|---|---|---|
Point 1 | Fine sandstone | 41 | 126 | 0.074825 | 4.751825 |
Point 2 | Fine sandstone | 57 | 110 | 0.125876 | 4.802876 |
Point 3 | Coarse sandstone | 68 | 99 | 1.248198 | 5.925198 |
Point 4 | Fine sandstone | 79 | 88 | 1.063534 | 5.740534 |
Point 5 | Medium sandstone | 96 | 71 | 1.170742 | 5.847742 |
Point 6 | Medium sandstone | 115 | 52 | 1.484356 | 6.161356 |
Point 7 | Coarse sandstone | 124 | 43 | 1.618336 | 6.295336 |
Point 8 | Fine sandstone | 133 | 34 | 1.567089 | 6.244089 |
Point 9 | Fine sandstone | 141 | 26 | 1.471666 | 6.148666 |
