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The uniaxial compressive strength of a rock under static loading often decreases with an increasing temperature at which the rock has been heat-treated before strength testing. This conclusion is drawn from a great number of experiments [1,2,4,8,9,11,17–19]. The higher the temperature is, the lower the strength. Some results for uniaxial compressive strength σ c and tensile strength σ t ...

Get PriceEmail contactTHE UNIAXIAL COMPRESSIVE STRENGTH OF SOFT ROCK D. S. Agustawijaya Lecturer, Department of Civil Engineering, Faculty of Engineering, Mataram University, Mataram, Indonesia Email: [email protected] ABSTRACT Soft rock is a term that usually refers to a rock material with a uniaxial compressive strength (UCS) less than 20 MPa. This low strength range might be

Get PriceEmail contact01/01/2007 Soft rock is a term that usually refers to a rock material with a uniaxial compressive strength (UCS) less than 20 MPa. This low strength range might be

Get PriceEmail contact04/06/2015 Estimating compressive strength. General rock failure criterion can be reduced to a few parameters dependent on lithology (m) and the uniaxial compressive strength (C 0).Lithology is commonly derived during log analysis, so m may be estimated (Table 1).What is needed still is an initial measure of rock strength provided by C 0. C 0 can be estimated from porosity or sonic velocities, but

Get PriceEmail contactTESTING OF INTACT ROCK FOR STRENGTH 2.1 Uniaxial Compression 2.2 Point Load Testing 2.3 Uniaxial Tension 2.4 Indirect Tension Tests 2.5 Shear Tests 2.6 Confined Compression Tests (Triaxial Tests) 2.7 Biaxial and Multiaxial Tests 2.8 Other Tests 3. PARAMETERS AFFECTING ROCK STRENGTH 4. FAILURE CRITERIA FOR INTACT ROCKS AND ROCK MASSES 4.1 Mohr Criterion

Get PriceEmail contactUniaxial compressive strength ( c), E-modulus and the factor m i in the Hoek-Brown failure criterion for rock masses Average values from tests Tests of rocks world of intact rock samples -wide* Scandinavian rocks tested at SINTEF / NTNU *** Rating of the factor m i ** c E E c Number of tests c E E c Number ROCK MPa GPa MPa GPa of tests ure Dolomite 86 38 443 8 110 49 443 2 10.1 Limestone 107 ...

Get PriceEmail contactFor the uniaxial or unconfined compressive strength test a right circular cylinder of the material is compressed between the platens of a testing machine as illustrated in Fig. 8.1. The compressive strength is then defined as the maximum load applied to crush the specimen divided by the cross-sectional area. Rock strength has been found to be size dependent because of the cracks and

Get PriceEmail contactUNIAXIAL COMPRESSIVE STRENGTH OF ROCK MATERIALS 1. SCOPE This method of test is intended to measure the uni- axial compressive strength of a rock sample in the form of specimens of regular geometry. The test is mainly intended for strength classification and characterization of intact rock. 2. APPARATUS (a) A suitable machine shall be used for applying and measuring axial load to

Get PriceEmail contactuniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) of rock for designing surface and underground structures. Determining these rock strengths is time- consuming and expensive, particularly for the preliminary studies of projects. For this reason, indirect tests such as Schmidt rebound number and, ultrasonic test are often used for predicting rock strength. Since

Get PriceEmail contactIt could be seen from the table that the uniaxial compressive strength and peak strain of the soft rock and hard rock are close to the aforementioned test results, which confirms the reliability of the simulation results and lays a foundation for the later triaxial compression simulation analysis. Thickness ratio (%) Uniaxial compressive strength (MPa) Peak strain (10 −2) Calculated value ...

Get PriceEmail contact01/01/2015 1. Introduction. Unconfined compressive strength (UCS) determination of rocks plays a significant role in the analysis of geotechnical problems such as dam and tunnel design, drilling and mechanical rock excavation .The UCS of the rock is determined directly by testing the compressive behavior of the rock specimens under axial load in the laboratory.

Get PriceEmail contactDefinition of uniaxial compressive strength of a rock mass The Generalized Hoek-Brown criterion is written as a ci ci m b s = + + s s s s s ' ' ' 3 1 3 (1) where s1 ' and s3 ' are the major and minor principal stresses respectively. sci is the uniaxial compressive strength of the intact rock pieces mi, s and a are material constants determined from the GSI rating Substituting s3 ' = 0 into ...

Get PriceEmail contactThere has been a lot of interest in the relationship between uniaxial compressive strength (UCS) and other properties of rock. Evaluation of rock parameters such as cohesion, Young’s modulus, angle of friction, and Poisson’s ratio is required for numerical modeling of rock. Finding empirical relations between these parameters with UCS has been focused. On the basis of the ranges of UCS ...

Get PriceEmail contactFor the uniaxial or unconfined compressive strength test a right circular cylinder of the material is compressed between the platens of a testing machine as illustrated in Fig. 8.1. The compressive strength is then defined as the maximum load applied to crush the specimen divided by the cross-sectional area. Rock strength has been found to be size dependent because of the cracks and

Get PriceEmail contactUNIAXIAL COMPRESSIVE STRENGTH OF ROCK MATERIALS 1. SCOPE This method of test is intended to measure the uni- axial compressive strength of a rock sample in the form of specimens of regular geometry. The test is mainly intended for strength classification and characterization of intact rock. 2. APPARATUS (a) A suitable machine shall be used for applying and measuring axial load to

Get PriceEmail contactuniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) of rock for designing surface and underground structures. Determining these rock strengths is time- consuming and expensive, particularly for the preliminary studies of projects. For this reason, indirect tests such as Schmidt rebound number and, ultrasonic test are often used for predicting rock strength. Since

Get PriceEmail contact5.2 Method C, uniaxial compressive strength of rock is used in many design formulas and is sometimes used as an index property to select the appropriate excavation technique. Deformation and strength of rock are known to be functions of confining pressure. Method A, triaxial compression test, is commonly used to simulate the stress conditions under which most underground rock masses exist.

Get PriceEmail contact** Point load tests on rocks with a uniaxial compressive strength below 25 MPa are likely to yield highly ambiguous results. Table 3: Values of the constant m i for intact rock, by rock group. Note that values in parenthesis are estimates. Rock mass properties 7 . Rock mass properties 8 Anisotropic and foliated rocks such as slates, schists and phyllites, the behaviour of which is dominated by ...

Get PriceEmail contactFailure in Uniaxial Compression: Rock examines under uniaxial compressive anxiety, on account of uneasiness centers around minor discontinuities, can fail in strain, in shear or in coupling of the weight and shear stresses. It relies on upon the presentation of the parts and the nervousness transport, the frustration is prompted being developed, shear or in coupling of shear and development ...

Get PriceEmail contactDefinition of uniaxial compressive strength of a rock mass The Generalized Hoek-Brown criterion is written as a ci ci m b s = + + s s s s s ' ' ' 3 1 3 (1) where s1 ' and s3 ' are the major and minor principal stresses respectively. sci is the uniaxial compressive strength of the intact rock pieces mi, s and a are material constants determined from the GSI rating Substituting s3 ' = 0 into ...

Get PriceEmail contactthe 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 COMPRESSIVE STRENGTH TEST The UCS is undoubtedly the geotechnical ...

Get PriceEmail contactThere has been a lot of interest in the relationship between uniaxial compressive strength (UCS) and other properties of rock. Evaluation of rock parameters such as cohesion, Young’s modulus, angle of friction, and Poisson’s ratio is required for numerical modeling of rock. Finding empirical relations between these parameters with UCS has been focused. On the basis of the ranges of UCS ...

Get PriceEmail contactuniaxial compressive strength (UCS) and Brazilian tensile strength (BTS) of rock for designing surface and underground structures. Determining these rock strengths is time- consuming and expensive, particularly for the preliminary studies of projects. For this reason, indirect tests such as Schmidt rebound number and, ultrasonic test are often used for predicting rock strength. Since

Get PriceEmail contactUniaxial compressive strength ( c), E-modulus and the factor m i in the Hoek-Brown failure criterion for rock masses Average values from tests Tests of rocks world of intact rock samples -wide* Scandinavian rocks tested at SINTEF / NTNU *** Rating of the factor m i ** c E E c Number of tests c E E c Number ROCK MPa GPa MPa GPa of tests ure Dolomite 86 38 443 8 110 49 443 2 10.1 Limestone 107 ...

Get PriceEmail contactInternational Journal of Rock Mechanics Mining Sciences 43 (2006) 554–561 Estimating the uniaxial compressive strength of a volcanic bimrock H. Sonmeza,, C. Gokceoglua, E.W. Medleyb, E. Tuncaya, H.A. Nefesliogluc aDepartment of Geological Engineering, Applied Geology Division, Hacettepe University, 06532 Beytepe, Ankara, Turkey bMedley GeoConsultants, 1554 Winding Way, Belmont,

Get PriceEmail contact5.2 Method C, uniaxial compressive strength of rock is used in many design formulas and is sometimes used as an index property to select the appropriate excavation technique. Deformation and strength of rock are known to be functions of confining pressure. Method A, triaxial compression test, is commonly used to simulate the stress conditions under which most underground rock masses exist.

Get PriceEmail contact** Point load tests on rocks with a uniaxial compressive strength below 25 MPa are likely to yield highly ambiguous results. Table 3: Values of the constant m i for intact rock, by rock group. Note that values in parenthesis are estimates. Rock mass properties 7 . Rock mass properties 8 Anisotropic and foliated rocks such as slates, schists and phyllites, the behaviour of which is dominated by ...

Get PriceEmail contactThe uniaxial compressive strength of a rock material constitutes the highest strength limit of the rock mass of which it forms a part. It is determined in accordance with the standard laboratory procedures. For the purpose of rock mass classification, the use of the well -known point load strength index can be useful as the index can be determined in the field on rock core retrieved from ...

Get PriceEmail contact25/06/2015 An understanding of rock strength is important for designing recovery plans for a reservoir and for developing an appropriate reservoir simulation.A detailed discussion of rock failure can be found in Rock failure relationships and Compressive strength of rocks.But the data needed for these methods may not be readily available, so there is a desire to use data available from well logs that are ...

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