shear strength is taken as one-half the compressive strength. In the cone test, a cone with an angle 0 is forced into the soil [Figure 12-4(b)] under a force (Q), which may be its own weight. The shear strength is obtained from the relation KQ . Soil …
The uniaxial compressive strength (UCS) of the rock is one of the most important rock properties in geotechnical and mining engineering. UCS of rock is the one essential parameter used for the characterization of the rock mass in various systems such as rock mass rating (RMR), Q-system, and Hoek–Brown failure criterion [].UCS is typical rock property used …
The primary purpose of the Unconfined Compression Test is to quickly determine a measure of the unconfined compressive strength of rocks or fine-grained soils that possess sufficient cohesion to permit testing in the unconfined state. This measure is then used to calculate the unconsolidated undrained shear strength of the clay under unconfined ...
Table 1: Spreadsheet for the calculation of . and . from triaxial test data Note: These calculations, together with many other calculations related to the Hoek-Brown ... 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 ...
The accurate determination of uniaxial compressive strength (UCS) plays a vital role in the initial design phase of rock engineering and rock geotechnics. Traditionally, this assessment entails costly, time-intensive and labor-demanding experimental tests. Consequently, there is significant promise in exploring machine learning techniques for UCS prediction, …
Empirical relations between rock strength and physical properties in sedimentary rocks Chandong Chang a,⁎, Mark D. Zoback a,1, Abbas Khaksar b,2 a Department of Geophysics, Stanford University, Palo Alto, CA 94305-2215, USA b GeoMechanics International, Inc., Perth, WA 6000, Australia Received 1 April 2005; received in revised form 27 November 2005; …
The uniaxial compressive strength (UCS) of rock is an important geotechnical parameter for engineering applications. However, how to determine the UCS simply and accurately has drawn the attentions of may researchers. ... Based on the calculation results, the L-type Schmidt hammer was suggested for use in UCS estimation, and the corresponding ...
Compressive Strength Compressive strength (qu = F u) of core in unconfined compression (uniaxial compression test) - D 2938* Triaxial compressive strength without pore pressure T 226 D 2664 Creep Tests Creep-cylindrical hard rock core in uniaxial compression - D 4341 Creep-cylindrical soft rock core in uniaxial compression - D 4405
The uniaxial compressive strength (UCS) is one of the important geo-mechanical variables of the intact rock that is used to assess the quality of rocks in civil and mining engineering excavations like tunneling, open pit and underground mining, underground space, and rock-cutting by tunnel boring machine or roadheader.Point load index strength test (PLI) …
The unconfined compression test is the most popular method of soil shear testing because it is one of the fastest and least expensive methods of measuring shear strength. It is used primarily for saturated, cohesive soils recovered from thin-walled sampling tubes. The test is not applicable to cohesionless or coarse-grained soils.
Rock abrasivity index (RAI) and uniaxial compressive strength (UCS) are two key parameters for assessing abrasivity and durability of building stones, respectively. Direct determination of these parameters is a time-consuming, tedious and costly task. Hence, indirect and nondestructive tests such as P-wave velocity (Vp) and Schmidt hammer rebound (SHR) …
Introduction The rock mass compressive strength is a measure of the peak load carrying capacity of a rock mass (i.e stress driven failure) and is likely to be a fraction of the intact rock ...
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 COMPRESSIVE ...
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 safety. To …
If the upper part of the rock, within a depth of about 5/4, is of lower quality, the value of this part should be used. Another practice that is normally followed is to base the allowable pressure on the unconfined compressive strength, qu, of the rock obtained in a laboratory on a rock sample. A factor of safety of 5 to 8 is used on qu to ...
Brown failure criterion for jointed rock masses is defined by: (1) where and are the maximum and minimum effective principal stresses at failure, is the value of the Hoek-Brown constant m for …
The other is to use a standard specimen to calculate the size correction factor. Three to five input parameters are commonly utilized in soft computation models to predict the UCS of rocks. ... The uniaxial compressive strength (UCS) of rock is one of the key parameters determining the mechanical behavior and failure characteristics of rocks ...
The maximum compressive stress that a material can withstand before it breaks is known as the compressive strength of the material. This number is important for engineers to know as it can help ...
Sixty- eight uniaxial compressive tests were conducted on weak-to-strong (5 MPa < UCS < 100 MPa) and very strong (UCS > 100 MPa) rock samples exhibiting wide ranges of elastic modulus (E = 6100 ...
The uniaxial strength, also known as the unconfined compressive strength, of a rock may be regarded as the highest stress that a rock specimen can carry when a unidirectional stress is applied, normally in an axial direction to the ends of a cylindrical specimen.It represents the maximum load supported by a specimen during the test divided by the cross-sectional area of …
rock strength to parameters measurable with geophys-ical well logs. The use of such relations is often the only way to estimate strength in many situations due to the absence of cores for …
In the construction processes of underground or mining engineering, the strength and deformation characteristics of rock masses are critical, and are usually described by the elastic modulus and uniaxial compressive strength (UCS) of rocks (Aladejare 2020).These parameters are vital for the engineering design, stability analysis, and classification in rock …
There are many tests that are used in the identification of the geomechanical properties of rocks. Examples of these tests are shown in Fig. 1.Among these tests, the point …
The unconfined compressive strength (UCS) of rocks is undoubtedly a key input parameter of numerous constitutive models predicting the stress of rocks (Hoek and Brown 1980, 1997, 2019; Hoek 1983; Hoek et al. 2002).Determining the UCS of a rock sample in the laboratory requires specialist equipment and intact rock samples free of fissures and veins …
The uniaxial compressive strength (UCS) is classified as one of the basic mechanical properties of rocks, which is widely used in mining and construction practice.
where σ ci is the uniaxial compressive strength, m i is a constant based on the rock type, σ 1 and σ 3 are the principal stresses. After conducting at least 3 triaxial tests in different lateral pressures, the best-fit envelopes of the criterion selected are plotted and the parameters of each one (cohesion, friction angle in M-C and m i, σ ...
The uniaxial compressive strength (UCS) of rock is an important parameter required for design and analysis of rock structures, and rock mass classification. Uniaxial compression test is the direct method to obtain the UCS values. However, these tests are generally tedious, time-consuming, expensive, and sometimes impossible to perform due to ...
Unconfined Compressive Strength, UCS, can be determined in the laboratory using the Triaxial Test or the Unconfined Compressive Strength Test. There are also correlations for UCS with shear strength as estimated from the field using Vane Shear Tests. With a conversion of 1 kips/ft 2 = 47.88 kN/m 2.
The Schmidt hammer is commonly used for the prediction of unconfined compressive strength and other mechanical properties of rocks from surface rebound hardness values since it is quick, easy, inexpensive, and non-destructive testing method. In this study, metamorphic, sedimentary, and igneous rock samples were collected from various locations …
IS 13365 ( Part1 ) : 1998 3.1.5 Ground Water Condition In the case of tunnels, the rate of inflow of ground water in litre per minute per 10m length of the tunnel
Rock Fracture and Rock Strength. Zong-Xian Zhang, in Rock Fracture and Blasting, 2016. 3.12.8 Rock Strength. Rock strength is useful in rock engineering, although it is not a material property. Two main reasons are: (1) strength is much easier to determine than fracture toughness; (2) the micro-scale failure mechanisms are similar for both strength and …
The dynamic compressive strength of rock materials increases with the strain rate. They are usually obtained by conducting laboratory tests such as split Hopkinson pressure bar (SHPB) test or drop-weight test. It is commonly agreed now that the dynamic increase factor (DIF) obtained from impact test is affected by lateral inertia confinement, friction confinement …
The uniaxial compressive strength (UCS) of rocks is one of the key parameters for evaluating the safety and stability of civil and mining structures. In this study, 386 rock samples containing four properties named the load strength (PLS), the porosity (Pn), the P-wave velocity (Vp), and the Schmidt hardness rebound number (SHR) are utilized to predict the …
