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1. Introduction. Deep resources such as oil, gas, and solid mineral have drawn more interest. Generally, the deeper drill is characterized by higher pressure and temperature, which make the drilling and borehole stability harder [1–7].However, in Mexico Bay, North Sea Basin, Sichuan Basin, and the South Sea of China [], for example, the …
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The analysis in Section 5 demonstrates that the temperature threshold of the tested granite under the confining pressure of 30 MPa is 70 °C, which is similar to the values observed without confining pressure. 45 The AE activity of the Beishan granite measured under high-temperature triaxial compression (P c = 5,10,30 MPa, T = …
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It can be seen from Fig. 9 that the long-term strength of a rock sample with a confining pressure of 10 MPa is 193.6 MPa. Based on the fitted curve, the creep strain rate at the long-term strength is 0.559 × 10 –7, which is less than 1.0 × 10 –7, which indicates that the creep strain rate conforms to the range that corresponds to the ...
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We characterized the strength and deformability of Wuyi granite based on Brazilian tests and axisymmetric compression tests under different confining pressures (0, 5, 10, 20, 25, and 30 MPa). Facilitated by a modified three-dimensional (3D) Hoek–Brown strength criterion, the 3D strength envelopes of the granite in the principal stress …
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Question: WORKOUTImmediate roof material in a certain coal mine comprises of a sandstone layer 40cm thick and isoverlain by 1.5m of another rock type more stronper/competent than the sand stone. Sandstone hastensile strength of 5Mpa and density of 2.5tm3.
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Ultimate tensile strengths vary from 50 MPa for an aluminum to as high as 3000 MPa for very high-strength steels. Fracture point: The fracture point is the point of strain where the material physically separates. At this point, the strain reaches its maximum value and the material actually fractures, even though the corresponding stress may be ...
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For this reason, fine-grained granite with high brittleness was specially selected. The granite specimens were collected from Hubei Province in Central China. The average bulk density, uniaxial compressive strength, tensile strength and thermal conductivity of granite are 2622 kg/m 3, 217.7 MPa, 11.6 MPa, 2.61W/mK, respectively.
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PDF | On Sep 1, 2012, Neil Chandler published Granite yield strength and post-yield damage based on plasticity. | Find, read and cite all the research you need on ResearchGate
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The result for bulk density and UCS test for granite and limestone are listed in Tables 1 and 2.The bulk density value range from as low as 2.46 g/cm 3 to a high of 2.59 g/cm 3 for granite and between 2.48 to 2.68 g/cm 3 for limestone as summarised in Table 3.The UCS value ranges from 35.97 to 59.77 MPa for granite and from 9.41 to 42.06 …
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Key Laboratory of In-Situ Property Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China ... the granite shear strength …
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the uniaxial compressive strength (UCS), and to propose appropriate Is50 to UCS conversion factors for different coal measure rocks. The rock strength determined by the PLT, like the load frame strengths that they estimate, are an indication of intact rock strength and not necessarily the strength of the rock mass. THE UNIAXIAL …
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The modelled strength of the intact granite is 360 MPa at a depth of 1400 m and increases to 455 MPa at 2200 m (using our estimate for the empirical m i term of 30, determined using triaxial and tensile strength measurements on the intact granite). Strength of the rock mass varies in accordance with the fracture density and the extent …
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Hoek Brown criterion for surface mining Page 5 Table 1.1: Field estimates of uniaxial compressive strength. Grade* Term Uniaxial Comp. Strength (MPa) Point Load Index (MPa) Field estimate of strength Examples R6 Extremely Strong > 250 >10 Specimen can only be chipped with a geological hammer Fresh basalt, chert, diabase, gneiss, granite,
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In underground tunnel construction, rocky slope excavation, mining, and other engineering projects, the retained ... Tensile strength (MPa) P-wave velocity (m/s) Granite 2.65 2.66 0.13 144.00 81. ...
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It is shown that the threshold temperature of strength and elastic modulus of granite are both 200 centigrade. Below this, the sample mainly undergoes the brittle …
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Granite dust is a waste material which is produced during crushing and grinding process of granite stone. The annual production rate of the Maddhapara Granite Mine is 1.65 million metric tons from ...
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Understanding the mechanical properties of rock at high temperature subjected to true triaxial compression is significant for studying the wellbore stability in developing hot dry rock resources. In this study, true triaxial compression tests were conducted on granite specimens at different temperatures (up to 400°C) and under …
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In the mining of geothermal resources, understanding the physical and mechanical behavior of a rock with preexisting thermal damage is necessary to control the stability of the mining process. Herein we report mechanical testing results on a granite subjected to eight initial thermal damage conditions. The results indicate that the P-wave …
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Uniaxial Compressive Strength (MPa) Granite. 100-250. Diorite. 150-300. Diabase. 100-350. Gabbro. 150-300. Basalt. 100-300. Gneiss. 50-200. Marble. 100-250. Slate. 100-200. Quartzite. 150-300. Sandstone. 20-170 ... International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts. 16, 2. Equipment Providers. Looking for ...
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International Journal of Rock Mechanics and Mining Sciences. Volume 182, October 2024, ... Uniaxial compressive strength, (MPa) 2713: 34.5: 0.21: 11.7: 112.6: ... Quantification of microcrack characteristics and implications for stiffness and strength of granite. Int J Rock Mech Min Sci, 100 (2017), ...
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The difficult-to-break granite, which is common in TBM excavation, mine construction, and oil and gas extraction, is chosen as the test rock sample. The dimension of the rock specimen is 400 mm × 200 mm × 40 mm, and its uniaxial compressive strength is as high as 193.5 MPa, which belongs to the category of extremely hard rock.
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Granite is one of the rock types commonly encountered in deep mining and used in laboratory experiments [38], [39].Therefore, in this study, a granite collected from Yueyang city, Hunan province, China was used as the test material, and its related fundamental mechanical parameters are listed in Table 1.By using an automatic X-ray …
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The elastic modulus ranges from 9.7 to 144 GPa, the uniaxial compressive strength ranges from 3.1 to 81.2 MPa, the tensile strength ranges from 1.11 to 7.79 …
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For this reason, fine-grained granite with high brittleness was specially selected. The granite specimens were collected from Hubei Province in Central China. …
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The 112 point exponential fit yields static fatigue limit for the average-strength specimen at 102 MPA or at 459/0 of strength. The 950 confidence boundaries are quite close at 95-109 MPa. The weakest member of the strength distribution (209 MPa) would eventually fail at 94 MPa between confidence limits of 88 and 100 MPa.
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1. Introduction. Deep resources such as oil, gas, and solid mineral have drawn more interest. Generally, the deeper drill is characterized by higher pressure and temperature, which make the drilling and borehole stability harder [1 – 7].However, in Mexico Bay, North Sea Basin, Sichuan Basin, and the South Sea of China [], for …
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The physical and mechanical properties of granite are obtained by the standard method. 48 The granite material has Young's modulus 48.2 GPa, density ρ 2650 kg/m 3, poison's ratio μ 0.26, uniaxial compressive strength σ c 139 MPa, tensile strength σ t 7.26 MPa and compressive wave speed 4532 m/s.
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2.2 Laser Irradiation Granite Specimen Test. The laser rock-breaking test platform used in this test is mainly composed of a continuous semiconductor laser and a three-axis CNC cutting platform, and the overall structure is shown in Fig. 2a. The laser has a maximum power of 5 kW and a wavelength of 915 nm, and the CNC cutting platform …
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High geostresses and stress gradients are the predominant stress conditions in deep excavation-disturbed rock masses. The aim of this study is to determine the triaxial compressive strength properties of hollow cylindrical granite specimens under a radially non-uniform confining stress field with different radial stress gradients …
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As shown in Fig. 13 (a), the shear strength of granite samples generally decreases as the joint persistency is varied from 0.0 to 0.90, through 0.25, 0.50 and 0.75. For example, when the joint persistency, k, is 0.0, which means that the granite sample is intact, the shear strength value is 14.70 MPa. With the joint persistency increasing to 0. ...
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