Research Article
Influence of Valleys Terrain on Pressure of Fully Mechanized Working Faces in Shallow Coal Seams
Table 3
Physical and mechanical properties of borehole strata.
| Lithology | Poisson’s ratio | Volume (kg/m3) | Elastic modulus (GPa) | Uniaxial compressive strength (MPa) | Internal friction angle |
| Mudstone | 0.24 | 2630 | 21 | 30 | 33 | Poststone | 0.20 | 2700 | 47 | 40 | 36 | Sandy mudstone | 0.23 | 2590 | 20 | 29 | 29 | Kern stone | 0.23 | 2810 | 40 | 35 | 29 | Coal | 0.29 | 1400 | 20 | 13 | 30 | Siltstone | 0.24 | 2490 | 22 | 37 | 31 |
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