The numerical tests suggest that the uniaxial compressive strength of rock is not affected by the grain size. For the notched Brazilian specimens, as the grain size increases, greater tensile strengths are obtained in both the static and dynamic tests. The particle size has a negligible impact on the static tensile strength of intact specimens.
The compressive strength of a rock is the maximum stress that it can withstand before it fails when subjected to a compressive load. Compressive strength is an important property of rocks in many …
Unconfined Compressive Strength (UCS) of intact rock has been considered as the main parameter in most rock mass classification systems and also as a high limit of the rock mass strength. Determining UCS using suggested standard methods is costly and time consuming mainly due to difficult sample preparation and destructive …
When this force exceeds the strength of the soil-rock cement, different pores within the specimen expand and interconnect. This results in an increase in the specimen porosity and a transformation of smaller pores into larger ones. ... The uniaxial compressive strength at different freeze-thaw cycles exhibited a strong exponential …
Rock strength is estimated from two common laboratory techniques: uniaxial compressive strength tests and triaxial or confined compressive strength tests. Uniaxial …
Uniaxial compressive strength is an important metric in rock mechanics and rock engineering, particularly in the evaluation of rock slope stability, tunneling design, and ore mining. On the other hand, the laboratory UCS test is time-consuming and costly.
The rock compressive strength (Li et al., 2018; Gao et al., 2022; Meng et al., 2021), tensile strength (Liu et al., 2022b), and fracture toughness (Liu et al., 2022a; Zhang et al., 2023a) of frozen-thawed rocks when subjected to dynamic impacts have garnered substantial attention in recent years. Dynamic compressive strength (DCS) is a crucial ...
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 …
However, the rock compressive strength appears to be a somewhat less sensitive parameter to subtle textural features of these rock as compared to elastic properties, such as compressional and shear wave velocities. While clay matrix-supported siliciclastics (wackes and shales) can be differentiated from grain-supported ones (clean …
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 ...
Rumelhart et al. (1986) proposed the BPNN algorithm, which is a multi-layer feed-forward ML technique. As shown in Fig. 1, the structure of the BPNN consists of one input layer, one or more hidden layers, and one output layer.The triaxial compressive strength of rocks is used as the output neuron in this study, while the temperature and confining pressure …
• Strength classification is based on strength of the rock (compressive strength & modulus of elasticity; Table 7.2) • 5 strength classes: A-E based on the overall rock …
Hawkins and McConnell (1992) carried out tests to determine the influence of the water content on the strength of 15 sandstones. They found that the relationship between water content and uniaxial compressive strength could be described by an exponential equation of the form: (2) σ c (w) = a e − b w + c where σ c (w) is the …
Crowning a single type of rock as the strongest in the world is more complicated than it might seem, mostly because there are many different ways to define strength. What are you doing to the rock to test its strength? Are you squeezing it? Pulling it apart? What if you're trying to scratch it? The answers to these question…
The uniaxial compressive strength (UCS) of rocks is a vital geomechanical parameter widely used for rock mass classification, stability analysis, …
The dynamic and total uniaxial compressive strength (UCS) of three types of specimens under various preloads were measured using the modified SHPB system. ... (FM) specimens were prepared to understand the end friction effect on measuring the dynamic compressive strength of rocks with static preload. Specimen S1 and S3 are …
These test methods investigate the rate dependence of compressive strength of rocks at low and high strain rates, respectively. A general understanding is that the compressive strength slightly increases with a higher strain rate at a low strain rate (e.g. < 5 s −1) and grows rapidly at a high strain rate (e.g. > 500 s −1).
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.
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 [1].The UCS of the rock is determined directly by testing the compressive behavior of the rock specimens under …
The uniaxial compressive strength (UCS) is an important index for rock classification and rock mass quality evaluation. As one of the indispensable mechanical parameters in rock mass engineering design and stability analysis, UCS had been included in various standards and engineering codes, and its research significance could not be …
Mining rock salt results in subsurface damage, which may affect the strength because of applied stress, anisotropy, and deformation rate. In this study, we used a Kolsky compression bar to measure the high strain rate response of bedded and domal salt at strain rates up to approximately 50 s −1 in parallel and perpendicular directions to …
These studies indicate that compressive strength is an important factor influencing penetration resistance performance, and for rock materials, their microstructure has a significant impact on ...
The unconfined compressive strength (UCS) of intact rocks is crucial for engineering applications, but traditional laboratory testing is often impractical, especially for historic buildings lacking sufficient core samples. Non-destructive tests like the Schmidt hammer rebound number and compressional wave velocity offer solutions, but ...
STRENGTH OF ROCK MATERIALS IN TRIAXIAL COMPRESSION I SCOPE 1.1 This standard covers the mothod for deterrni nation of strength of cyhndncal rock specimens subjected to triaxial compression. This test provides Individual points on the failure (peak strength) envelope from several tests. From this the value of the internal friction angle '" …
0.2 The unconfined compressive strength test is primarily an index test for strength classification of rock materials. Although it may be used in the laboratory, it is mainly intended for field measurements on rock core and outcrop specimens. The apparatus used in the test is light and
According to the compression testing results, carbonate rocks exhibited more substantial rock resistance than those of sandstone and shale rocks, distinguished by the largest uniaxial compressive strength (being 108.07 MPa), as shown in Fig. 2 a. Among the three kinds of rocks, shale specimens had the smallest compressive …
Consequently, the bimrock with a rock-type matrix is the typical cemented matrix-rock mixture, and the conceptual strength model of welded and unwelded cemented matrix-rock mixtures is illustratively shown in Fig. 1 referring to the work of Sonmez et al. 11 The matrix-rock boundary is an essential factor in the mesomechanical framework of …
Scope1.1 This test method specifies the apparatus, instrumentation, and procedures for determining unconfined compressive strength of intact rock core specimens.1.2 The values stated in inch-pound units are to be regarded as the standard. The SI values gi
Uniaxial compressive strength (UCS) is one of the most widely used rock mechanical parameters in rock engineering like design and construction of foundations, tunneling, slope stability investigations, etc. UCS is also the only parameter to assess rock material strength in Rock Mass Rating (RMR) proposed by Bieniawski (1989).However, …
Experimental data in Fig. 1 b indicate that the compressive strength of rock-like materials increases gradually with strain-rate in the low strain-rate regime (10 −4 –10 1 s −1), but turns to rapid increase in the intermediate (10 1 –10 2 s −1) and high (10 2 –10 4 s −1) strain-rate regimes.For a given rock material, it has been shown that there exists a …
