Numerical investigation of the influence of specimen size …
Bahrani and Kaiser (2016) used GBM to investigate the influence of specimen size on the strength of intact rocks and rocks with defects in unconfined conditions [14]. They found that the strength ...
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Discontinuities and rock strength | SpringerLink
The influence of low discontinuity tensile strength is clearly evident at overhanging and at steep non-overhanging faces in fractured rock masses, such as the one shown in Figure 9.1. Free faces such as this release the compressive stresses that may have existed in the rock, and allow the development of tensile stresses beneath overhangs.
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Rheological mechanical properties and its constitutive
Rheological mechanical properties of the soft rock are affected significantly by its main physical characteristics-clay mineral. In this study, taking the mudstone on the roof and floor in four typical mining regions as the research object, firstly, the clay mineral characteristic was analyzed by the X-ray diffraction test. Subsequently, rheological …
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The influence of microwave treatment on the compressive …
Hassani and Nekoovaght 13 and Hassani et al. 14 conducted comprehensive laboratory tests to investigate the influence of microwave radiation on the temperature profiles and the strength reduction in hard rocks such as norite, granite, and basalt. The samples were exposed to the microwave energy of 1.2, 3 and 5 kW for 10, 65 and 120 s …
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Influence of grain size heterogeneity on strength and …
3.1 Deformation Behavior and Rock Strength. The influence of grain size heterogeneity on the simulated stress-strain responses and rock strength evolutions of the numerical models will be examined and discussed in this section. ... That is why the rock strength of homogeneous model is higher than that of heterogeneous model …
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(PDF) Influence of Water Content on the …
5%. It is apparent that the strength of the rock is very. sensitive to the water content; an increase in water. content of as little as 1% from the dry state can have. a marked effect on strength ...
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Influences of Schistosity Structure and Differential
Request PDF | Influences of Schistosity Structure and Differential Stress on Failure and Strength Behaviors of an Anisotropic Foliated Rock Under True Triaxial Compression | Foliated rocks are ...
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Influences of petrographic and textural properties on the strength …
In this study, the petrographic characteristics affecting the strength of granitic rocks were investigated and a new mineralogical-based model was suggested for the prediction of uniaxial compressive strength (UCS) in line with the obtained data. Increase in quartz and alkali feldspar contents with decrease in plagioclase content …
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The effects of rock-infill interfacial properties on the compressive
2)The properties of rock-infill interfacial contacts have clear influences on the compressive strength of rock specimens. When full-cohesive interface is provided, the UCS of rock remains the same with various flaw inclined angles, which demonstrates the rock strengthening mechanism of infill.
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The influence of microwave treatment on the compressive …
Cutting hard rocks has some problems such as low penetration rate and high wear rate of cutting tools. These problems can be solved by the microwave treatment of hard rocks during cutting. In this study, the effects of microwave treatment were investigated on the strength of nine different igneous rocks. First, the uniaxial compressive strength …
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How do geological structure and rock type influence coastal …
Structure. Geological structure includes the way that layers of rocks are folded or tilted. This can be an important factor in the shape of cliffs. Faults are cracks in rocks. Enormous tectonic pressures can cause rocks to 'snap' rather than fold (bend), and movement (or displacement) happens on either side of the fault.
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Thermal Influence on Mechanical Properties of Granite: A …
To fully understand the thermal influences on rock permeability, both thermally induced fracture closure and microcracking need to be considered in more detail. ... Pradhan SP, Singh TN (2011) Tensile strength of rock under elevated temperatures. Geotech Geol Eng 29:1127–1133. Article Google Scholar Wai RSC, Lo KY, Rowe RK …
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Influences of confining pressure and bedding angles on the …
Compressive strength4.1.1. Influence of confining pressure on compressive strength. In the development of rock mechanics, many scholars have proposed and improved various strength criteria. The linear Mohr-Coulomb strength criterion [16], the parabolic Mohr-Coulomb strength criterion [17] and the Hoek-Brown strength criterion …
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Influence of Some rock properties on blasting
Influence of Some rock properties on blasting performance: A case study ... The laboratory experiments reveal the uniaxial compressive strength value of collected ore sample 98.09 Mpa with elastic ...
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Influence of humidity conditions on shear strength of clay rock …
The shear strength of rock discontinuities strongly depends on the water content especially when the rocks contain clay materials. To assess the decrease in the mechanical properties of clay-infilled discontinuities due to water saturation, a series of direct shear tests was performed using an advanced shear box that allows the injection …
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Aspects of rock strength | Bulletin of Engineering Geology …
Abstract. This paper discusses some important factors to be considered when undertaking rock strength tests and describing the strength of a rock as assessed during field investigations. It highlights the lack of consistency in the commonly used descriptive categories and draws attention to the disparencies which can arise when rocks are …
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Analysis of Influences of Weak Joints and Confining Pressure on Rock
The strength of rock mass with weak joints is mainly under control of the joints occurrence, the joints dip and the rock strength, and great influenced by the confining pressure. A higher strength ...
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Dynamic Shear Strength of Rock Joints and Its Influence on …
The dynamic shear strength of rock joints was analyzed theoretically following the Coulomb-Navier criterion and further investigated experimentally by split Hopkinson pressure bar (SHPB) tests ...
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Influence of Axial Stress on Borehole Rockburst: Insights
The influence of σ 2 on rock strength is usually characterized by an increase in failure strength with the increase of σ 2, followed by a strength plateau and then a strength drop soon after any further increase of …
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Statistical damage model of rocks reflecting strain softening
The damage threshold of rocks is used as a criterion to determine whether the rock is damaged or not. The damage threshold is related to the deformation characteristics in the pre-peak elastic stage at a low-stress level. In addition, after the damage, the rock still has residual strength, which is the main factor affecting the …
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Tensile Strength of Rock Under Elevated Temperatures
A clearly visible upward trend and downward trend of the strength before and after 100°C can be observed. At 90°C, the maximum increase in tensile strength was calculated as 21.45% while at 130°C a rapid fall in tensile strength up to 25% was found as compared to the strength reduction at 110°C (12.93%) (Fig. 5 ).
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Influence of Dolomite Rock Powder and Iron Tailings …
Meanwhile, the influence of dolomite rock powder and iron tailings powder on the compressive strength of concrete was investigated. The electric flux of concrete was determined to estimate the chloride ion permeability. The scanning electron microscope (SEM) and X-ray diffraction were obtained to investigate the hydration of cement paste ...
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Shear damage mechanisms of jointed rock mass: a …
In natural rock masses, numerous randomly distributed and varying-sized joints significantly influence the mechanical properties of the rock. In recent years, many scholars have conducted many ...
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Influence of some rock strength properties on jaw crusher …
The influence of rock strength properties on Jaw Crusher performance was carried out to determine the effect of rock strength on crushing time and grain size distribution of the rocks. Investigation was conducted on four different rock samples namely marble, dolomite, limestone and granite which were representatively selected …
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Influences of Loading Condition and Rock Strength to the …
The influences of displacing angle, joint gap, and rock strength to the performance of rebar bolts and D-Bolts are evaluated in this study. A new method was developed to apply pull and shear loads to the bolt specimen in any combination so that a displacing angle can be established in the range from 0 (pure pull) to 90° (pure shear).
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Using Artificial Neural Networks to Predict Influences of
The induced heterogeneity changes the rock properties. This paper targets the gap in the existing literature regarding the adopting of artificial neural network approaches to efficiently and accurately predict the influences of heterogeneity on the strength of 3D-printed rocks at different strain rates.
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Influence of explosive energy on the strength of the rock …
A change in the fragment strength will influence the efficiency of the grinding circuit in further breaking those fragments. ... The third measure of rock strength was obtained using the JKMRC ore abrasion test (Napier-Munn et al., 1996). This test was conducted on each of the samples that were subjected to a Drop Test.
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Experimental study on influence of host rock strength on …
To study the effect of the host rock strength on the shear performance of micro-NPR steel bolted rock joints, three representative natural rocks, red sandstone, marble, and granite, were used (Fig. 3 a)pared to the cement mortar, concrete, and other similar materials commonly used in this test, natural rock can more accurately …
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Influence of grain size and basic element size on rock …
Bahrani N, Kaiser PK (2016) Numerical investigation of the influence of specimen size on the unconfined strength of defected rocks. Comput Geotech 77:56–67. Article Google Scholar Bahrani N, Kaiser PK (2017) Estimation of confined peak strength of crack-damaged rocks. Rock Mech Rock Eng 50:309–326
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Influence of grain contents on the dynamic strength of rock …
The dynamic strength (at strain rates from 1 × 10 2 to 5.98 × 10 2 s −1) is related to not only the grain content but also the degree of grain breakage, denoted as the TG in this study. Increasing the strain rate increased the TG, increasing the strength in turn. This study clarified the effect of grain breakage on the dynamic strength.
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