1 Introduction
2 Tensile Testing of Rock
3 Test Set-Up
3.1 Specimen Preparation
3.2 Testing Apparatus Set-Up and Verification
Sample | Tensile strength (MPa) | Average tensile strength (MPa) |
---|---|---|
Uniaxial tension test
| ||
U-1 | 2.05 | 2.08 |
U-2 | 1.98 | |
U-3 | 1.83 | |
U-4 | 2.08 | |
U-5 | 2.36 | |
U-6 | 2.15 | |
Brazilian test
| ||
B-1 | 2.52 | 2.44 |
B-2 | 2.29 | |
B-3 | 2.37 | |
B-4 | 2.54 | |
B-5 | 2.49 |
4 Direct Tension Tests on Incipient Discontinuities
4.1 Samples with Incipient Bedding Planes
Sample | Height (mm) | Tensile strength (MPa) | Percentage to UTS of intact rock (%) | Average tensile strength (MPa) |
---|---|---|---|---|
BH1-1 | 149 | 0.67 | 32.2 | 1.45 |
BH1-2 | 132 | 1.22 | 58.7 | |
BH1-3 | 112 | 1.69 | 81.3 | |
BH1-4 | 110 | 1.82 | 87.5 | |
BH2-1 | 152 | 1.51 | 72.6 | |
BH2-2 | 150 | 1.79 | 86.1 |
4.2 Samples with Incipient Joints
Sample | Diameter (mm) | Tensile strength (MPa) | Percentage to UTS of intact rock (%) | UTS of rock bridges (MPa) |
---|---|---|---|---|
BH70J1 | 70 | 0.63 | 30.3 | 2.10 |
BH70J2 | 70 | 0.48 | 23.1 | 2.09 |
BH70J3 | 70 | 0.90 | 42.3 | 2.14 |
BH70J4 | 70 | 0.55 | 26.4 | 2.12 |
BH70J5 | 70 | 1.34 | 64.4 | 2.09 |
BH70J6 | 70 | 0.60 | 28.8 | 2.07 |
4.3 Samples Containing Mineral Veins
Sample | Diameter (mm) | Tensile strength (MPa) | Average strength (MPa) |
---|---|---|---|
DR50C1 | 50 | 0.49 | 0.84 |
DR50C2 | 50 | 0.62 | |
DR50C3 | 50 | 1.15 | |
DR50C4 | 50 | 1.09 | |
DR50C5 | 50 | 7.13 | |
DR70C1 | 70 | 0.29 | 0.28 |
DR70C2 | 70 | 0.44 | |
DR70C3 | 70 | 0.11 | |
DR70C4 | 70 | 6.68 |