The estimation of uniaxial compressive strength conversion factor of trona and interbeds from point load tests and numerical modeling

Rock mass properties. Rock mass properties. Introduction. Reliable estimates of the strength and deformation characteristics of rock masses are. required for almost any form of analysis used for the design of slopes, foundations and. underground excavations. Hoek and Brown (1980a, 1980b) proposed a method for obtaining estimates of the strength ...

Empirical equations proposed for predicting UCS and Brazilian tensile strength (BTS) from BPI by the previous researchers are summarized in Table 1.Gokceoglu and Aksoy [21] showed that BPI could be used as an alternative parameter to rate intact rock strength in the Modified-RMR system. Sonmez and Tunusluoglu [22] indicated that …

As such, conversion factors between the UCS and I s50 have been proposed by numerous researchers and have proven to be rock-dependent. For example, Chau and Wong (1996) observed from experimental data that the ratio between the UCS and I s50 of Hong Kong granite was 12.5.

In many geo-engineering fields, the uniaxial compressive strength (UCS) of a rock material is the parameter most commonly used to define a rock's mechanical strength. Several international standards have been developed for determining this value, which require the tested material to have certain minimum dimensions and shapes. In many …

strength conversion factors are mostly preferred to achieve uniaxial compressive strength values [3]. Uniaxial strength ... formations clay stone based rock. For this purpose 208 point ... Gypsum [25] UCS=5.575 I s(50) +21.92 The factors that are used in the calculation of the uniaxial compression strength value are often associated with this type

The point load (PL) test is generally used for estimation of uniaxial compressive strength (UCS) of rocks because of its economic advantages and simplicity in testing. If the PL index of a specimen is known, the UCS can be estimated using conversion factors. Several conversion factors have been proposed by various researchers and they are …

The mean values of uniaxial compressive stress results varied between 47.5 and 81.5 and the mean values Brazilian test results varied between 4.12 and 8.15 MPa for Sandstone, Claystone, and ...

The UCS to I S50 conversion factor for interbeds has a value of "25.96". This value is very close to some of the reported values (Broch and Franklin, 1972, Hassani et al., 1980, ISRM, 1985). The trona conversion factor is also in agreement with Sabatakakis et al. (2008) and Singh et al. (2012) who revealed that strength conversion factor is ...

conversion between the mechanical and optical rebound values based on work done by Winkler and Matthews ... UCS = 0.4367e(0.05R*) Granite (Grade I to IV) 2 to 33 0.437 0.05 23 76 . Title 2 / 3 2. Rock Schmidt RS8000 Type L …

Where, F is a size correction factor which is calculated as: After each corrected PL strength index is calculated, the two highest and two lowest values are excluded (given that 10 or more tests have been conducted on the tested material) and the average I S50 is derived. Estimation of Uniaxial Compressive Strength (UCS) based on I S50

posed the value of 24 for conversion of PLI to UCS for various rocks that they tested, which may be misleading as Fig. 1 Point load testing with specimen dimensions (after Peng and Zhang 2007) Table 2 Conversion factor between UCS and PLI obtained from zero-intercept regression analysis Rock type Geological age of the rocks Conversion factor ...

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 …

The number of samples tested for each rock type and the statistical data regarding the UCS, ITS, PLA and PLD values are presented in Tables 3 and 4. According to Table 3, the average UCS values ...

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.

Download scientific diagram | Correlation between UCS and IS50 values from publication: CORRELATIONS BETWEEN GEOMECHANICAL PROPERTIES AND PHYSICAL INDICES FOR SOME HIGH-GRADE METAMORPHIC ROCKS ...

The UCS values of the samples ranged between 1.27 and 23 MPa, with an average value of 6.79. While the average value of PLI was 0.5 MPa values varied from 0.0085 to 3.17 MPa. ... Oztruk H, Altinpinar M (2017) The estimation of uniaxial compressive strength conversion factor of trona and interbeds from point load tests …

Bloc de granite Facteur de conversion air/eau des salissures et très rugueux et des prismes octogonaux et carrés de longueur infinie en Obtenir le prix Pedo Logie scribd Les deux conversion factor (C) The UCS test is commonly used as an easy and less sophisticated among all three compression test types Other tests are also needed if Get …

The present paper has developed a new multivariate linear regression and adaptive neuro-fuzzy inference processing to predict UCS for weathered granite grade III based on simple input data from point load index, Schmidt rebound hardness, and P wave velocity. Data from 85 rock core samples of this granite type have been selected. By …

In the size correction factor (F) the power n for irregular lump is corrected as 0.8 for marble lumps and the n value for pink and white granite is 0.9 and 1.4 respectively. For diametral and ...

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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 …

The conversion factor between UCS and BPI c was higher than the proposed value of 5.1 by Ulusay et al. 14 Results show that in estimating UCS from BPI c, the equation proposed by Sonmez and Tunusluoglu, 15 has a better performance among suggested equations for BPI, because of considering "m i " parameter of Hoek and …

experimental data that the ratio between the UCS and I s50 of Hong Kong granite was 12.5. Table 8 Table 8 presents the commonly adopted e mpirical equations for the rela tionship between the UCS and

For a rock with a given Hoek-Brown strength envelope as defined by the parameters UCS and m i, it is possible to convert a given rate of confining stress, ... CD/UCS for Stanstead Granite is approximately 75%, ... Factors that influence the apparent peak strength in unloading tests were described, including the following: …

T. N. Singh et al [1] had run numerous tests on various rock types that one of which is shale. UCS versus PLA graphs have been plotted and at last different conversion factors for different rock types are presented. Also, it is concluded that a conversion between 21-24 for harder rocks and 14-16 for softer rocks should be used.

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 …

Correlations between (a) BPIc and UCS, and (b) Is (50) and UCS for all three rock types (i.e granite, schist and sandstone) together (all strength values are in MPa).

For sedimentary rocks, the conversion factor UCS = 22.6 * I s(50), with a coefficient o f determination of R 2 = ... [Natural stone test methods -Determination of uniaxial compressive strength.

Proposed correl ation equations for UCS and PLI . Author (s) Suggested correlation equation D andrea et al (1965) UCS=15.3 PLI+16.3 Deer and Miller (1966) UCS=20.7 PLI+29.6 Broch and Franklin (1972) UCS=23.7 PLI (Various rock types) Bieniawski (1975) UCS=23.9 PLI (Sandstones) Hassani et al (1980) UCS=29 PLI (Sedimentary rocks)