lab tests for rock strength

The strength and failure of rock masses remain ambiguous owing to their complex structure. Investigating the strength and failure of jointed rock mass is a continuing concern within rock engineering. In this study, effects of joint intensity and joint connectivity on the strength of rock-like material with complex discrete joints were …

The uniaxial compressive strength (UCS) is classified as one of the basic m echanical properties of rocks, which is. widely used in mining and construction practice. For exam ple, it allows ...

The Brazilian splitting method is recommended by the ISRM as the standard method for measuring the dynamic tensile strength of rocks 34. Disk-splitting tests were performed on all types of rock ...

The rock cores recovered from the boreholes are generally taken to the laboratory for strength and deformability tests. The common core size designations and their nominal diameters are given in Table 9.1. The core barrel may consist of single, double or triple tubes to minimize the disturbance.

Significant rock properties are defined as those properties that are of concern to the design and construction in rock: â ¢ Compressive strength â ¢ Shear strength â ¢ Hardness (durability) â ¢ Compressibility â ¢ Permeability Some common laboratory tests for rock include slake-durability, ultrasonic pulse velocity, point load, direct ...

Rock Mech Rock Eng DOI 10.1007/s00603-014-0631-8 ORIGINAL PAPER A Laboratory-Testing-Based Study on the Strength, Deformability, and Dilatancy of Carbonate Rocks at Low Confinement G. Walton • J. Arzúa • L. R. Alejano M. S. Diederichs • Received: 28 March 2014 / Accepted: 18 July 2014 Ó Springer-Verlag Wien 2014 Abstract A servo ...

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 …

Rock Manual. The Rock Manual provides common technical information on properties of rocks, field and laboratory investigations, and testing of rocks used as foundations and materials for dams, tunnels, canals, and many other types of structures built for Reclamation. The Rock Manual consists of two parts: Part 1, still to be …

The Direct Shear Test is an experimental procedure conducted in geotechnical engineering practice and research that aims to determine the shear strength of soil materials. Shear strength is defined as the maximum resistance that a material can withstand when subjected to shearing. Generally, the Direct Shear Test is considered one of the most ...

Significant rock properties are defined as those properties that are of concern to the design and construction in rock: â ¢ Compressive strength â ¢ Shear strength â ¢ Hardness …

Typical laboratory tests involve determination of physical properties (density, porosity, water content), hardness and abrasiveness, durability, strength …

The point load test (PLT) is an accepted rock mechanics testing procedure used for the calculation of a rock strength index. This index can be used to estimate other rock strength parameters. The focus of this paper is to present the data analysis used to correlate the point load test index (Is 50) with the uniaxial compressive strength (UCS ...

Following are common laboratory tests for determining strength of rocks: Unconfined compression tests for rocks. Triaxial compression test for …

The triaxial test, which determines the shear strength and stiffness of soil and rock, is one of the most versatile and widely performed geotechnical laboratory tests that is used in geotechnical design. Two parameters of shear strength are required for the design of slopes and for many other analyses: calculation of the bearing capacity of any ...

The Unconfined Compression Test is a laboratory test used to derive the Unconfirmed Compressive Strength (UCS) of a rock specimen. Unconfirmed Compressive Strength …

The peak tensile strength obtained was −13.5 MPa at a confining stress of 5 MPa. The tensile strength under no confinement was −5.5 MPa. The maximum strength obtained in the compressive stress ...

2. Tests On Rock a. Unconfined Compression Test on Rock. The unconfined compression test is the type of laboratory test that is used to determine the strength of rocks. Unconfirmed compressive strength of rocks may be defined as the maximum axial compressive stress that the specimen can withstand under zero confining …

Introduction. Point Load (PL) is a test that aims at characterizing rock materials in terms of strength. It is an index test, meaning that it can be performed relatively quickly and without the necessity of sophisticated equipment to provide important data on the mechanical properties of rocks. Index tests have been widely used in soil ...

The lab tests were carried out on a large number of four different types of rock samples ranging from nearly isotropic to anisotropic. The lab tests were done in parallel to numerical simulations [17], which enable a detailed interpretation of the results and a specification of the influencing factors. 2. Rock material—selection and ...

Lab B had available a multipurpose testing machine TIRAtest28500 with a capacity of 500 kN for compressive loading, and 100 kN for tensile loading. The cylindrical metal caps where the cylindrical rock specimens are placed, can be connected to the machine's crosshead via threaded rods with ball joints (Fig. 2b). Lab B performed the …

strength tests, 20 unconfined compressive strength tests, and 4 each triaxial strength tests at confining pressures of 1, 2, 5, 10, 20, 40 and 80 MPa. Thus there were 58 data points in all ...

Isotropically Consolidated Undrained Test: BS1377-8: An effective strength test where the sample is consolidated to a mean effective stress and the undrained strength and pore water pressure is measure. In an undrained test the volume remains constant. Stability of slopes and design of retaining structures. Isotropically Consolidated Drained ...

As described in Section 2.5, the typical approach taken to time-to-failure and long-term strength testing includes conducting a series of preliminary UCS tests to determine an average strength for the rock being tested, followed by a series of constant stress tests, which are held until the rock yields. These tests are then normalized by the ...

laboratory testing of rock strength. new equipment and testing techniques have been developed to investigate the basic strength of rock. the effect of varying the intermediate principal stress on the strength appears appreciable in the case of crystalline rocks such as granite. failure of hollow cylinders of rock under conditions of high ratios ...

Grain size effect on rock strength is a topic of great interest in geotechnical engineering. A consensus obtained from earlier laboratory tests is that rock strength generally decreases with the ...

1.1 This test method establishes requirements and laboratory procedures for performing direct shear strength tests on rock specimens under a constant normal load. It includes procedures for both intact rock strength and sliding friction tests, which can be performed on specimens that are homogeneous, or have planes of weakness, …

A; b Lab. B; c Lab. C, and d Lab. D (the specimen corresponding to the highlighted curve is indicated in brackets in the legend, with 'G' denoting granite) +4 Stress–strain curves from DTS ...

1. Introduction. Conventional triaxial testing to evaluate the strength of intact rock under confinement is conducted using a stress path whereby a constant minimum principal stress (σ 3) is applied to the specimen followed by a monotonic increase of the maximum principal stress (σ 1) in the axial direction.However, as many authors have …

Point Load (PL) is a test that aims at characterizing rock materials in terms of strength. It is an index test, meaning that it can be performed relatively quickly and without the …

Based on the laboratory measurements of strength and deformation of rocks, and Miller (1966) established a two parame­ ter classification system. The two parameters are …

Laboratory tests are carried out to determine rock properties. Since rock properties are a key input for rock mechanics design in civil, mining, and petroleum …

The most known is the Brazilian test (Briševac et al., 2015). The Brazilian Test is a laboratory test conducted in rock mechanics to indirectly determine the tensile strength of rocks. The rock is exposed to a compressive load in such a way as to cause tensile stress on the rock sample. The result of the Brazilian test is the tensile rock ...

Laboratory rock testing is performed to determine the strength and elastic properties of intact specimens and the potential for … See more

Direct shear (DS) is a common geotechnical laboratory test used to determine strength and deformation properties of rock discontinuities, such as normal and shear stiffness, peak and residual shear strength, and dilation. These are used as inputs for discontinuous geomechanical numerical models to simulate discontinuities discretely …

For most engineering design, material properties such as strength, Young's modulus and Poisson's ratio are of critical importance. Establishing these parameters often proves problematic when considering materials such as concrete, and more acutely rock, where the size of the engineering structure far exceeds the size of any laboratory test …

Rock strength and porosity have good correlations for various rocks, and porosity can be obtained from lab tests or from density and sonic logs. In the following equations, the rock strength UCS is in MPa and porosity is in percent (%). For shales in the North Sea (geologically young and weak shales, mostly high-porosity Tertiary shales), Horsrud …

The rock mass strength and the rock mass deformation modulus are difficult to estimate directly in the field or by laboratory testing. Different scholars such as Bieniawaski (1989), Hoek et al. (2002) and Barton (2002) have suggested empirical equations for the estimation of both rock mass strength and rock mass deformation modulus.