Determination and applications of rock quality …
Accepted Manuscript Determination and applications of rock quality designation (RQD) Lianyang Zhang PII: S1674-7755(16)00022-6 DOI: 10.1016/j.jrmge.2015.11.008
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Accepted Manuscript Determination and applications of rock quality designation (RQD) Lianyang Zhang PII: S1674-7755(16)00022-6 DOI: 10.1016/j.jrmge.2015.11.008
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A database of 127 training and 32 testing datasets collected from NATM-3 of the tunnel was constructed. The input parameters are the Uniaxial Compressive Strength (UCS), Rock Quality Designation ...
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Rock quality designation (RQD) is widely adopted as a fundamental tool in characterizing rock masses since it was devised in 1964. Since the conventional RQD calculation is limited due to its …
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Rock quality designation (RQD) was introduced by Don in the mid-1960s as a means of using diamond core to classify rock for engineering purposes. Subsequently, it was incorporated into the …
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The weighted average RQD of 40 m roof rock is 61% whose significance is given in Table 1 (Fig. 5). A 4.5 m upthrow fault (F1) is encountered on the north side of the extracted and proposed CM panels and is traversing from west to east. The strike of the formation in the study area varies from WNW-ESE to NW-SE and dips towards NE.
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Determining permeability of fractured rocks is a focal point in engineering projects. Many methods have been developed for direct in situ determination of the hydraulic parameter; nevertheless, especially in the preliminary stages of rock mass characterization, empirical correlations are used to estimate the rock permeability. This study proposes a …
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Results indicate that compressive strength, tensile strength, and Young's modulus values for the sandstones studied are closely related (r>0.7) to their density, percent absorption, total pore ...
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The rock quality designation (RQD) is a commonly used index for the description of rock mass fractured state. The RQD was initially introduced for civil engineering applications, and it has been quickly adopted in mining, engineering geology as well as geotechnical engineering. The success of the RQD is in great part, due to its simplicity. This paper …
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Rock Quality Designation (RQD) is among the widely used measures of the quality of rock masses and can be derived through Monte Carlo stochastic process-based fracture network simulations. However, repeated simulations can yield variable RQD results. Here, we introduce a four-step approach that incorporates class ratio analysis to …
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Determining Rock Quality Designation (RQD) ... 3.2.5 sound core—any core which is fresh to moderately weathered and which has sufficient strength to resist hand breakage. 4. Summary of Test Method ... PO Box C700, West Conshohocken, PA 19428-2959, United States. L7HK6 WDQGDUGV KWWSV˛ VWDQGDUGV LWHK DL ' RFXPHQW3 UHYLHZ.
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RQD signifies the degree of jointing or fracture in a rock mass measured in percentage, where RQD of 75% or more shows good quality hard rock and less than 50% show low quality weathered rocks. RFQ is calculated by taking a rock core sample from a borehole and lengths of all sound rock pieces which are minimum 100 mm long are summed up …
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Rock engineers use the uniaxial compressive strength (UCS) of rocks prevalently in the design of surface and underground structures. UCS is one of the most important engineering parameters in rock mechanics, and it is used to characterize and examine the behaviors of solid rocks. Considering the difficulty of conducting tests on …
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Along RQD profile Q, three deep weathered zones of 200, 180 and 190 m thickness were revealed at distance of 30–180, 320–410 and 550–700 m, whereas other …
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It is shown that the empirical methods based on RQD tend to give deformation modulus values close to the lower bound (conservative) and unconfined compressive strength values in the middle of the corresponding values from different empirical …
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Based on mapping of rock formations by 17 independent professionals at different locations in Australia and South Africa, it is shown that differences in assessed …
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A thorough evaluation of rock mass strength is necessary for the smooth progress of large-scale engineering projects. In engineering construction, bearing strength of foundation rock needs to be graded to ensure the successful development of engineering structures (Aydan et al. 2014; Olayanju et al. 2017).The bearing capacity of rock mass is …
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Rock-strength and physical properties of Norites of the Merensky and Bastard Units, western Bushveld Complex A.H. Wilson; A.H. Wilson School of Geological Sciences, University of KwaZulu-Natal, Durban, South Africa, ... (RQD). In addition, there is an unexpectedly strong correlation between UCS values and both …
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Finally, the empirical methods based on RQD are used to determine the deformation modulus and unconfined compressive strength of rock masses at five different sites including 13 cases, and the ...
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Such rocks may be recovered intact, with RQD=100, yet their lateral strength may be one-sixth of their axial (6). Since the most severe loading applied to coal mine roof is normally lateral, caused by horizontal stress, bedding plane shear strength is a critical parameter. Unfortunately, bedding plane shear strength is almost never tested
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Fracture spacing (or RQD) Uniaxial compressive strength (or axial Point Load Testing) Diametral Point Load Testing. The moisture sensitivity adjustment has also been …
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In determining the RQD index only sound core pieces longer than 100 mm are to be considered (Figs. 1 and 2). Accordingly, RQD enables core logging as well as evaluation of the degree of jointing along the core drill hole, the so-called "core run", whereby RQD gives an average measurement of the degree of jointing along the total core run length
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Abstract. The knowledge of the main mechanical constants of a rock. mass (such as strength, deformability and the Poisson' s ratio) is one of the most important for rock engineering design on or ...
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The RQD can also be used for calculating the Geological Strength Index (GSI): on the basis of several studies, Hoek et al. [7] suggested the following simple formula for GSI calculation: GSI = 1.5 ...
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Hence, us ing this equatio n, data ana lysis was carried out to find the relatio nship be tween RQD andf racture frequ enc y in Monz onit e Porph yry. Th e graph and eq uation deri ved from this ...
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Rock Quality Designation (RQD) is a measure of quality of rock core taken from a borehole. RQD signifies the degree of jointing or fracture in a rock mass measured in …
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Six parameters are used to classify a rock mass: uniaxial compression strength, RQD, spacing of discontinuities, condition of discontinuities, orientation of discontinuities, and …
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Section snippets Background: directional dependence and upscaling of RQD. The RQD rating ( et al., 1967) provides a quantitative measure of the degree of jointing or fracturing of rock mass from boreholes, consisting of 100 times the ratio between the total length of core pieces larger than 100 mm and the total core run length.
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Scope. 1.1 This test method covers the determination of the rock quality designation (RQD) as a standard parameter in drill core logging of a core sample in addition to the commonly obtained core recovery value (Practice D2113 ); however there may be some variations between different disciplines, such as mining and civil projects.
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