Research Article
Research on Characteristic Stress and Constitutive Equation of Confined Sandstone during Damage Evolution Based on Energy Evolution Analysis
Table 1
Comparison of characteristic stress determined by the three methods.
| Confining stress (MPa) | Peak stress σp (MPa) | Characteristic stress (MPa) | Difference (MPa) | Ratio of characteristic stress to σci (%) | EPM | LSM | VSM | EPM | LSM | VSM | σcc | σci | σcd | σcc | σci | σcd | σcc | σci | σcd | σcc/σp | σci/σp | σcd/σp | σcc/σp | σci/σp | σcd/σp |
| 5 | 126.00 | 26.80 | 52.15 | 87.80 | 28.40 | 52.25 | 85.80 | 1.60 | 0.10 | −2.0 | 21.27 | 41.39 | 69.68 | 22.54 | 41.47 | 68.10 | 10 | 160.00 | 20.35 | 62.70 | 100.00 | 22.40 | 65.30 | 105.00 | 2.05 | 2.60 | 5.00 | 12.72 | 39.19 | 62.50 | 14.00 | 40.81 | 65.63 | 20 | 194.00 | 18.70 | 77.00 | 135.50 | 21.82 | 77.50 | 137.00 | 3.12 | 0.50 | 1.50 | 9.64 | 39.69 | 69.85 | 11.25 | 39.95 | 70.62 | 30 | 234.00 | 12.15 | 90.00 | 165.50 | 15.80 | 91.00 | 170.00 | 3.65 | 1.00 | 4.50 | 5.19 | 38.46 | 70.73 | 6.75 | 38.89 | 72.65 | Mean | — | — | — | — | — | — | — | 2.61 | 1.05 | 2.25 | — | 39.68 | 68.19 | — | 40.28 | 69.25 |
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