USING THE POINT LOAD TEST TO DETERMINE THE …
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 …
Cutting efficiency of extremely hard granite by high
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.
Permeability partitioning through the brittle-to-ductile
Mechanical data and measured permeability. Cylindrical samples of Lanhélin granite with a diameter of 20 mm and height of 42 mm were subjected to elevated …
A review of test methods for uniaxial compressive strength …
For example, needle penetration test is useful to estimate the strength of soft rocks or rocks with a low UCS, while the indentation test and scratch test show a comparably wide range of applicability. Generally, almost all these test methods (except NPT 1) can be used to estimate the strength of rocks with UCS = 10–100 MPa. Thus, …
Thermophysical and Mechanical Properties of Granite and …
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 …
Static compression behavior and strength weakening …
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 …
Influence of some rock strength properties on jaw crusher …
Received 29 August 2009; accepted 12 November 2009 *Corresponding author. Tel: 86 516 83885948 E-mail address: [email protected] doi: 10.1016/S1674-5264(09)60185-X Influence of some rock strength properties on jaw crusher performance in granite quarry OLALEYE B M * Department of Mining Engineering, Federal …
Predicting Uniaxial Compression Strength (UCS) Using …
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 …
Strength of Materials
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 ...
Granite yield strength and post-yield damage based on …
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
Dynamic mechanical properties of different types of …
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. ...
-Uniaxial compressive strength (MPa) of the test specimens …
The average values obtained for the granite samples studied were 86 MPa, 132 MPa and 104 MPa, for collection points 1,2 and 3, respectively. ... View in full-text Get access to 30 million figures
Mechanical properties of granite at high temperature …
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 …
Experimental investigation on fractal characteristics of …
At the moment of rockburst failure, the stress level of the granite sample initially damaged at 25 ℃ is σ1 = 152 MPa, σ2 = 45 MPa and σ3 = 0 MPa, whereas the stress …
Mechanical property and thermal degradation mechanism of …
The collected experimental data given in Fig. 10 includes strength, peak strain, elastic modulus, and Poisson's ratio of the Kuru granite 50 (KG), gneiss granite …
Strength Characteristics and Double-Yield Elastoplastic …
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 …
Shear Strength and Energy Evolution of Granite under Real …
Key Laboratory of In-Situ Property Improving Mining of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China ... the granite shear strength …
Triaxial strength and deformability of intact and increasingly …
1. Introduction. The Hoek–Brown failure criterion is an empirical relation that characterizes the stress conditions that lead to failure in intact rock and rock masses. 1, 2, 3 Unlike the also popular Mohr-Coulomb failure criterion, it is non-linear, and so better reflects rock strength as derived from laboratory triaxial tests. However, the main breakthrough …
Dynamic uniaxial compression tests on a granite
Dynamic uniaxial compression tests for the Bukit Timah granite in Singapore were conducted at four loading rates (10 0, 10 1, 10 3 and 10 5 MPa/s). It was found that the compressive strength increases from 205 MPa to 235 MPa with loading rate increasing from 10 0 to 10 5 MPa/s. Evidence also indicates that there are small changes in the …
STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES
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 …
Strength and dilation of jointed granite specimens in servo …
Strength and dilation of jointed granite specimens in servo-controlled triaxial tests. ... For σ 3 =2 MPa, peak strength for the jointed cores was approximately 50% of that for the intact cores; meanwhile ... Proceedings of the 6th international symposium on ground support in mining and civil engineering construction, Cape Town; 2008, p. 37–60.
Mechanical properties of granite at high temperature …
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.
Solved WORKOUTImmediate roof material in a certain coal mine …
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.
Granite
Granite is a type of common industrial natural stone. The graph bars on the material properties cards below compare granite to other natural stone materials (top) and the entire database (bottom). ... 2200 MPa 320 x 10 3 psi. Elastic (Young's, Tensile) Modulus. 70 GPa 10 x 10 6 psi. Flexural Strength. 24 MPa 3.5 x 10 3 psi. Poisson's …
Experimental Study of the Triaxial Strength Properties of …
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 …
Impact strength characteristics of granite under combined …
Mechanical characteristics during static loading at different confining pressures. Figure 4 presents the stress-strain loading results of the granite sample at different confining pressures. When the applied air pressures are 0.25 MPa, 0.3 MPa, 0.35 MPa, and 0.4 MPa, the maximum strain rate is 125 s −1 and the minimum strain rate is …
The long-term strength of lac du bonnet granite
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.
Pillar Strength in Underground Stone Mines in the …
strength equation can be used to design stable stone mine pillars provided the rock conditions are similar to those included in the study. 1. Introduction. There are more than 120 operating underground stone mines in the United States that use the room-and-pillar method of mining. Mining is typically conducted in flat laying or gently
Effect of artificially induced microcracks near the rock …
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), ...
Mechanical property and thermal degradation mechanism of granite …
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 = …