Purpose To determine the uniaxial compressive strength of rock (qu = F u = F C). Procedure In this test, cylindrical rock specimens are tested in compression without lateral confinement. The test procedure is simila r to the unconfined compression test for soils and concrete. The test specimen should be a rock cylinder of length-to-width ratio ...

The purpose of this study was to clarify the relationships between results of index tests and uniaxial compressive strength (UCS) in hydrothermally altered soft rocks of the Upper Miocene, which are typical of the soft rock found in northeastern Hokkaido, Japan. Index tests were performed using point load testing machine and needle penetrometer with irregular lump specimens under forced-dry ...

The uniaxial compressive strength for the rock mass, σc, rockmass, can be expressed by setting σ3 = 0 in Equation 2.1 thus obtaining σc, rockmass =σc s . (2.2) The uniaxial tensile strength of the rockmass, σt, rockmass, can be found by setting σ1 = 0 in Equation 2.1, thus yielding c (m m s) t 4 2 2, rockmass = − + σ σ . (2.3)

However, the uniaxial compressive strength test is expensive and time consuming. Moreover, the uniaxial compressive strength test cannot be performed in the field. In order to solve this kind of problem, many foreign researchers investigated the use of the point load strength test for the estimation of uniaxial compressive strength of rock.

Uniaxial Compressive Strength Standard index property (q u =σσσu = σσσσc) Analogous tests in concrete and soil (unconfined compression test). ASTM 4543. ISRM 1979, Suggested methods for determining the uniaxial compressive strength and deformability of rock materials. Int J Rock Mech Min Sci Geomech Abs 16(2), sid 135-140.

RE: uniaxial compressive strength vs bearing pressure. fattdad (Geotechnical) 9 Dec 09 09:14. unconfined compressive strength represents the value sigma 1 minus sigma 3 (i.e., the diameter of a Mohr's circle when sigma 3 equals 0). The corresponding shear strength would be half this value (i.e., the radius of the Mohr's circle).

12%The rock uniaxial compressive strength (UCS) is the basic parameter for support designs in underground engineering. In particular, the rock UCS should be obtained rapidly for underground engineering with complex geological conditions, such as soft rock, fracture areas, and high stress, to adjust the excavation and support plan and ensure construction …

The uniaxial compressive strength of intact rock specimen of homogenous and isotropic rocks such as granite, sandstone, basalt and etc had been well published. Substantially, all the findings were based on the study conducted on a single rock type that ranges from hard to weak rocks. Unfortunately, little study has been conducted on anisotropic ...

The rock uniaxial compressive strength (UCS) is the basic parameter for support designs in underground engineering. In particular, the rock UCS should be obtained rapidly for underground engineering with complex geological conditions, such …

strength is the most commonly measured strength parameter and this is also true of rock specimens. For 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 ...

Compressive Strength Of Rock. THE UNIAXIAL COMPRESSIVE STRENGTH OF SOFT ROCK D S Agustawijaya Lecturer Department of Civil Engineering Faculty of Engineering Mataram University Mataram Indonesia Email agustawijaya ABSTRACT Soft rock is a term that usually refers to a rock material with a uniaxial compressive strength UCS less than 20 MPa.

Uniaxial compressive strength ( c) and deformation modulus of rocks Average values from tests of intact rock samples Tests of rocks world-wide Scandinavian rocks tested at SINTEF c E E c of tests Number c E c Number ROCK MPa GPa MPa GPa of tests ure Dolomite 86 38 443 8 110 49 443 2

Unconfined compressive strength (UCS) of rocks is a crucial parameter in designing geotechnical structures. Owing to difficulties in obtaining proper samples for UCS test as well as the point that conducting UCS is relatively expensive, the use of indirect methods for UCS estimation has drawn considerable attentions. This review paper is aimed to briefly highlight different proposed predictive ...

1.1 These four test methods cover the determination of the strength of intact rock core specimens in uniaxial and triaxial compression. Methods A and B determine the triaxial compressive strength at different pressures and Methods C and D determine the unconfined, uniaxial strength.

The uniaxial compressive strength (UCS) of rock is one of the essential data in engineering planning and design. Correctly testing UCS of rock to ensure its accuracy and authenticity is a prerequisite for assuring the design of any rock engineering project. UCS of rock has a broad range of applications in mining, geotechnical, petroleum, geomechanics, and other fields of engineering.

Uniaxial compressive strength (UCS) of a rock is one of the most important parameters representing the bearing capacity of rock mass. Its variation is explained by a number of factors including mineral composition. It can be also defined as the threshold value for a rock and/or any other material to be failure under the external forces.

The rock uniaxial compressive strength (UCS) is the basic parameter for support designs in underground engineering. In particular, the rock UCS should be obtained rapidly for underground ...

STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1. INTRODUCTION 2. TESTING 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.

Soft rock is a term that usually refers to a rock material with a uniaxial compressive strength less than 20 MPa, and a conversion factor of 14 is proposed for soft rock materials. 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 influenced by physical characteristics, such as size ...

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 influenced by physical characteristics ...

Unconfined Compressive Strength of Intact Rock Core Specimens1 This standard is issued under the fixed designation D 2938; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.

Definition 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 ...

As a special geomaterial, the uniaxial compressive strength (UCS) is an important input parameter used in rock/soil engineering designs, as well as the shear strength. Sonmez et al.10 carried out some tests on volcanic bimrock to study the relationship between UCS and volumetric block proportion, and thendevelopedan empiricalapproachfor the deter-

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 influenced by physical characteristics ...

International 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

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, …

Biteghe Chandryl Uniaxial compressive strength test Page 2 fChapter 1 Basics on rock mechanics This introductory chapter define different parameters which characterize a rock. It also presents devices which measure displacements. 1.1 Basic definitions 1.1.1 Strain and Stress Stress The term stress (σ) is used to express the loading in terms of ...

determined. Therefore, to investigate material mechanics and gain experience in uniaxial testing, we performed compressive and tensile tests on alloys, pure metals, and ceramics, and calculated their Young's modulus, yield stress, ultimate tensile strength, and elastic strain energy density. 1.1 Uniaxial testing

rock sample uniaxial compressive strength and deformability. The interdependence of uncertainty contribution is analyzed and guides for improving measurement uncertainty are given. The achieved uncertainties are compared to typical uncertainties in the determination of concrete and metallic material compressive strength and deformability.

The strength of these samples decreased with increasing joint dip angle from almost the uniaxial compressive strength of intact material to the strength of blocks which had joint dip angles >40° (Table 2). The Strength Reduction Factor (SRF) is defined as the model mass strength to intact material strength under the uniaxial compressive loading.

The Stimson and Murray rocks are lithified fine sandstones and coarse silty mudstones, respectively, with varying compressive strengths. Thomson et al. (2013, 2014) illustrated that the energy per unit volume needed to break the bonds of a volume …

5.2 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.

uniaxial compressive strength ci of the intact rock pieces, value of the Hoek-Brown constant m i for these intact rock pieces, and value of the Geological Strength Index GSI for the rock mass. Intact rock properties For the intact rock pieces that make up the rock mass, equation (1) simplifies to: 0.5 ' ' 3 1 3 1

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 ...

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