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199621 · Permeability-RQD-fracture aperture chart. equation (2) yields RQD= 82%. This RQD value, together with the 0.44mm average fracture aperture yields from Figs 2 and 3, p = 0.01, i.e. 1% and k = 10-4 as 10-2 Darcy. Another practical use of these charts appears when the conventional aquifer tests yield the conductivity value and scanline ...
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2024614 · AARD has been associated with mining capital equipment for over 30 years. AARD emerged from the Boart Longyear group – responsible for designing and manufacturing its first hydraulic rock drill in the early 1980s. Under the management of an experienced team, AARD has built a comprehensive product range to complement …
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2015107 · Abstract. The Q-system for characterizing rock exposures and drill-core, and for estimating single-shell support and reinforcement needs in tunnels, caverns and mine roadways has been widely used by engineering geologists and mining engineers. In the last ten years, a slightly modified Q-system called Q-slope was tested by the authors, …
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2014926 · RQD should only be calculated over individual core runs, usually 1.5 metrers long. Figure 1. Procedure for determining RQD, after Deere and Deere (1988). RQD was originally introduced for use with NX-size core (54.7 mm) and a threshold value of 100mm is used. Over the years, several correction factors have been introduced to …
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2009121 · The directivity of RQD, which means the value of the RQD obtained from drilling cores or scanlines with different orientations can be different for a given site, is usually regarded as a drawback by researchers and engineers. ... International Journal of Rock Mechanics and Mining Sciences, Volume 75, 2015, pp. 73-81. Yu Wang, Adeyemi …
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2024627 · The RQD has many applications in mining, engineering geology as well as geotechnical engineering. Rock quality designation is also used to obtain the tunneling conditions. ... Therefore, RQD = (640/1200)x100 = 53% which is fair quality rocks, i.e. rocks are moderately weathered.
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2018121 · 1. Introduction. Rock Quality Designation (RQD) 1 is a rock quality index used in tunnel support/reinforcement design, prediction of in-situ modulus 1., 2., 3. finding allowable foundation contact pressures and fracture frequency, and as a parameter of RMR, 4 Q, 5 and Geological Strength Index (GSI) 6 rock mass classification systems. Hence, …
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2021920 · The RQD is defined as the ratio (in percentage) of the total length of sound core pieces that is 0.1 m (4 inch) or longer to the length of the core run. Besides the direct method for deter-mining RQD from coring, different indirect methods are also available for evaluating RQD. For determination of RQD using core boring, the International
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198481 · Rock quality designation (RQD) and geological strength index (GSI) values are lowest for highly and completely weathered igneous rocks. On the other hand, RQD and GSI values increase from moderately weathered to fresh igneous rocks. Assessment of rock mass classification system for blastability is useful for mining sustainability.
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201184 · The total core recovery (TCR) is defined as the pro-. portion of core recovered to the total length of the. drilled run. The core run is the length reported by the. driller as the actual depth ...
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