Two rock types including Shale and Marl stone have been utilized in this research. Correlations between UCS and PLI in this study are verified with proposed equation by pervious researchers. Key w ords : Point Load Test (PLT), Uniaxial Compressive Test (UCT), Point Load Index(PLI), …
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A conversion factor of carbonate rocks in the linear regression without intercept for UCS–PLI, UCS–BTS, UCS–SHR, and UCS-E was observed as 14.32, 7.26, 1.71, and 3.52, respectively.
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Standard. From the numbers indicated in the Standard, a general conversion factor of 0.75 may be inferred to correct H/D = 1 results to equivalent H/D= 2 results. For lower values of compressive strength (0.4 to 8 MPa) the conversion factor varies between 0.75 and 0.83. The Standard does not indicate any correction for the diameter per se.
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In order to estimate uniaxial compressive strength, index-to-strength conversion factors are used. These factors have been proposed by various researchers and are dependent upon rock type. ... 68 UCS 66 1,000 65 NG 160 386 NG Conversion Factor 14.7 18 12.6 17.4 12.6 8 15 24 23.7 21-22 30 29 23.4 20 23.9 20 14.1 Reference in Choi and Hong, 1998 ...
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To obtain the unconfined compressive strength (UCS) from point load testing (PLT) a conversion factor is commonly used; UCS = conversion factor * I s. ODOT research (Shakoor and …
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Rock types investigated are granite collected from Tumpat, Kelantan and limestone from Pandan Indah, Kuala Lumpur. The samples of granite and limestone are in fresh state (grade 1). …
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sbm granite ucs conversion factor.md; Find file Blame History Permalink b · f661b88d dushusbm authored Nov 02, 2022. f661b88d ...
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The linear regression analysis results which consists conversion factor and correlation coefficient for each rock type are presented in Table 2. Results and Discussion Having studied the UCS versus PLA graphs and ITS versus PLD graphs for different rocks it becomes quite clear that, the conversion factors are different for different rock types.
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In order to estimate uniaxial compressive strength, index-to-strength conversion factors are used. These factors have been proposed by various researchers and are dependent upon rock type. …
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The result for bulk density and UCS test for granite and limestone are listed in Tables 1 and 2.The bulk density value range from as low as 2.46 g/cm 3 to a high of 2.59 g/cm 3 for granite and between 2.48 to 2.68 g/cm 3 for limestone as summarised in Table 3.The UCS value ranges from 35.97 to 59.77 MPa for granite and from 9.41 to 42.06 MPa for limestone.
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The ratings based on both UCS (which is preferred) and point load strength index are given in Table 6.1. UCS may also be obtained from the point load strength index tests on rock lumps at the natural moisture content. See Table 8.13 for average UCS values of a variety of rocks. The pH value of groundwater may affect the UCS in saturated conditions.
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The conversion factor coefficients determined in the conversion of hardness values to each other provide more reliable resul ts than the prediction models created . Figure 5.
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In the case of pink and white granite the correction factors are F=(De/50)0.9 and F=(De/50)1.4 respectively. ... with the UCS was analysed to propose appropriate Is50 to UCS conversion factor for ...
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The ISRM method tends to overestimate the strength of rocks with higher strength, with a deviation of around 50% for oolitic limestones, granite, and pyroxenite; therefore, The International Society for Rock Mechanics recommends that the conversion factor (k) between I s(50) and UCS of 24 is not applicable for high-strength rocks.
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reported by Smith (1997) in which the correlation factor varied between a value of 8 for rocks with UCS of less than 1000 psi (6.9 MPa) to a value of 24 for rock samples with UCS of more than 6000 psi (41.5 MPa). Similar studies (Akram, and Abu Bakar, 2007) showed high differences in correlation factors for the same rock
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Brock and Franklin (1972) and Bieniawski (1975) had found that the uni-axial compression strength (UCS) can be estimated from the point load index using a correlation factor of 24 …
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406.2 Point Load Test. To obtain the unconfined compressive strength (UCS) from point load testing (PLT) a conversion factor is commonly used; UCS = conversion factor * I s.ODOT research (Shakoor and Admassu, 2010) has found that for Ohio bedrock use a conversion factor of 24 for competent rocks (sandstones and limestones) and 12 for incompetent rocks (shales …
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It is found that the index-to-strength conversion factors are rock dependent. This study presents the correlation between UCS and Is(50) of granite rock samples originating from a site located …
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UCS/PLI ratio of 11 for soft rocks (R2 = 0.4) in Brisbane, whereas a ratio of 23 is the most common ratio quoted in the international literature. A UCS to Young's modulus conversion factor in the range of 200 to 500 ( & Miller, 1966) is typically ap-plied to approximate the Young's modulus from UCS.
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The findings indicate that using the conversion factor (k) recommended by ISRM to predict the UCS of rocks may significantly underestimate the actual strength of rocks in intricate mining ...
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The Is(50) value is known to correlate well with UCS. Various studies have come out with correlation between UCS and Is(50) . It is found that the index-to-strength conversion factors are rock dependent. This study presents the correlation between UCS and Is(50) of granite rock samples originating from a site located at Seremban, Negeri Sembilan.
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relationship between UCS and the point load strength could be expressed as: UCS = (K) Is50 = 24 Is50 (2) Where K is the "conversion factor." Subsequent studies found that K=24 was not as universal as had been hoped, and that instead there appeared to be a broad range of conversion factors. Table 1 summarizes published results obtained for ...
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Point load index (Is) has been commonly used for predicting uniaxial compressive strength of intact rocks (UCS) because Is is easy and quick test performed on lump specimens. For this reason, many empirical equations in the literature to estimate the uniaxial compressive strength from the point load index have been proposed for the last five decades. In this study, …
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Kaya and Karaman (2016) obtained conversion factors of PLI to UCS to the tune of 12. 98, 17.68, and 15.32 for pyroclastic, volcanic, and plutonic igneous rocks, 18.55 and 13.51 for chemical and ...
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23, [70][71][72][73][74][75] Although the ISRM suggested that the conversion factor between the UCS and I S (50) varies between 20 and 25 7, numerous researchers have shown that the factor has a ...
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The various soft-computing models proposed in the literature for the prediction of the UCS of granite are presented in Table 3, which shows details of the machine learning algorithm, the input ...
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UCS ¼ kI sð50Þ ð2Þ where k is the index-to-strength conversion factor. Besides the y = ax form, the y = ax ? b form was also experi-mentally confirmed by some researchers (Kahraman and
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The uniaxial compressive strength (UCS) is an important factor in the design and construction of surface and underground structures. However, the method employed to measure UCS is time consuming ...
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Generalized Hoek-Brown. The Generalized Hoek-Brown strength criterion is described by the following equation:. where: is a reduced value (for the rock mass) of the material constant (for the intact rock) and are constants which depend upon the characteristics of the rock mass. is the uniaxial compressive strength (UCS) of the intact rock pieces
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Table 2: Typical values of Uniaxial Compressive Strength for a various number of rocks (from Attewell & Farmer 1976). References. ASTM D7012-14e1, (2014).Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core Specimens under Varying States of Stress and Temperatures, ASTM International, West Conshohocken, PA.
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For example, the PLT to UCS conversion factor can vary from as low as 8 to as high as 30, while the ITS to UCS conversion factor values vary between 2.7 and 50 [43,44]. This implies that the conversion factor is a rock characteristic parameter and not a universal value; therefore, its applicability must be assessed on a case by case basis.
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developed with a UCS to PLT Is(50) conversion factor of 10.18 and may be applied to e stimate the strength of the Sudanese sandstone formation. The developed correlation is in good agreement with few of the many methods published for similar rock types which indicates that large errors may result in from applying an inappropriate UCS prediction ...
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From the literature, it is evident that for different rock types with specific geology, different conversion factors are to be used to predict UCS from Is (50). The Schmidt rebound …
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