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 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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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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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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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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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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UCS value along with the corresponding failure mode of the granite specimens is given in Table 2 and Fig. 7a. The dominant failure mode in granite up to the UCS value of 120 MPa is axial...
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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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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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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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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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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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Furthermore, these results also show that the conversion factor to convert a PLI to a UCS value can vary for both concrete and granite samples by up to , depending on the …
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3 Tables 1 and 2 show the conversion factors between UCS and PLA for shale and limestone rocks from several studies, respectively [6, 7, 8, 9].
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Furthermore, these results also show that the conversion factor to convert a PLI to a UCS value can vary for both concrete and granite samples by up to , depending on the irradiation time and heating (Fig. 10 b). Therefore, a fixed conversion factor for PLI to UCS, as various approaches summarized in Ref. 84 suggest, seems even more ...
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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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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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At present, there are three main conversion relational function between sandstone I s(50) and UCS: the zero intercept linear function, the non-zero intercept linear function and the power function ...
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where k is the index-to-strength conversion factor. Besides the y = ax form, the y = ax + b form was also experimentally confirmed by some researchers (Kahraman and Gunaydin 2009; Basu and Kamran 2010; Gunsallus and Kulhawy 1984).An exponential form of y = ax b was also reported by Grasso et al. ().A prediction equation similar to Eq. can be used to correlate …
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The experimental setup and failure pattern of the granite samples under the uniaxial compression tests are given in Fig. 4 e and f, and the granite specimens failed with distinct conjugate diagonal macroscopic fracture surfaces. Five compression tests are conducted to yield every UCS result for the rocks listed in Table 2.
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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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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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Uniaxial compressive strength (UCS) for rocks plays a vital role in both preliminary and final design stages of rock and geotechnical engineering projects such as dam, rock mass excavation, tunnel, slope stability and foundation of infrastructures (Bieniawski, Z.T., 1975, Cargill, J.S. and Shakoor, A., 1990).Besides, UCS is also an important parameter to assess rock …
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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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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 UCS–BPI conversion factor for this correlation is 5.1. In this study, the relation between UCS and BPI was investigated for pyroclastic rocks. ... tensile strengths of granite, schist and ...
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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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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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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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