Table 1 Mechanical parameters of the strata
From: Effect of bolting on roadway support in extremely weak rock
Name | Bulk density (average)/(t/m3) | Porosity (%) | Compressive strength (average)/MPa | Tensile strength (average)/MPa | Apparent cohesion (average)/MPa | Internal friction angle/(°) | RMR | GSI | Q |
|---|---|---|---|---|---|---|---|---|---|
Mudstone/carbon mudstone | 1.66–2.14 (2.0) | 26.20–54.11 | 0.12–5.12 (1.71) | 0.06–0.39 (0.12) | 0.24–0.39 (0.31) | 25.16–29.01 | 16 | 10 | 0.0125 |
Siltstone | 2.01–2.65 (2.2) | 17.48–27.13 | 0.64–8.00 (2.26) | 0.07–0.61 (0.34) | 0.23–0.50 (0.38) | 13.70–25.50 | 13 | 8 | 0.0105 |
Coal | 1.16–1.35 (1.3) | 25.40–45.72 | 1.18–9.44 (3.44) | 0.35–1.13 (0.56) | 0.42–1.02 (0.66) | 27.05–32.03 | 22 | 18 | 0.0167 |