UCS and PLT data concerning foliated rocks in the literature [36,42] plotted on the same diagram confirms that, indeed, for foliated rocks, the UCS and the PLT can be related to each other. The zero-intercept regression equation obtained for each data set has given conversion factors of seven (current data set), 12 and 20 . This difference ...

They concluded that a conversion factor of 21–24 should be used for harder rocks and 14–16 for softer rocks. Wood and Shaw (2012) investigated the …

However, conversion factor k is non-unique (varies between 8 and 30 for PLS to UCS conversions and between 2.7 and 50 for the ITS to UCS conversion) and depends on the degree of anisotropy of the ...

Introduction. Point Load (PL) is a test that aims at characterizing rock materials in terms of strength. It is an index test, meaning that it can be performed relatively quickly and without the necessity of sophisticated equipment to provide important data on the mechanical properties of rocks. Index tests have been widely used in soil ...

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 ...

Strength (UCS). It is often estimated on the field or trough Index-to-strength conversion factors proposed by various researchers for a specific rock type. The research presented in the paper involved field estimation of Uniaxial Compressive Strength using Schmidt rebound hammer and Point Load laboratory testing on limestone rock samples.

For determining the full stress strain curve ISRM (1999) suggests 20:1. Blanks and McNamara (1935) performed tests on cylindrical mass concrete specimens with a height to diameter ratio of 2:1 ...

Histogram showing hte difference between UCS predicted by the PLT using equation 5, and the 95% confidence interval of the measured UCS. The zero bar includes all cases that fell withing the 95% CI. Table 4 shows the conversion factors (K) obtained from zero-intercept regression analyses on various subsets of the data.

Vallejo et al. (1989) Sandstone 420 PLT and 21 UCS 17.4 . Smith (1997) ... For weak Simsima limestone of average UCS valu es between 5.0 ... index-to-strength conversion factors are used. These ...

Hawkins and Olver carried out similar tests on sedimentary rocks from the UK and reported the conversion factor as 26.5 for limestone and 24.8 for sandstone, which are higher compared with the results obtained in this case. Based on the present study, it was found that the relation between PLI and UCS varies for different rock types, …

In the study cored rock specimens were tested for UCS tests, Point Load tests (PLT) and Schmidt Rebound Hammer Tests (SRHT). All the tests' results were analysed using statistical techniques to ...

In order to improve the UCS prediction accuracy, 30 sets of regular cylindrical specimen tests between PLS and UCS are conducted on limestone mines. The …

UCS = K . Is50 (2) The conversion factor K was determined using linear regression analysis of data collected for 15 different rock types; and was found to be about 24. Since then, this value has been ... Limestone: 11.1 (Akram and Bakar 2007), 17.7 to 27.1 ((Brautigam et al. 1998), and 21.9 (Rusnak and Mark 2000)

In the literature, conversion factors on different sedimentary, igneous and metamorphic rocks can be found, but no study exists on trona. In this study, laboratory UCS and field PL tests were carried out on trona and interbeds of volcano-sedimentary rocks. Based on these tests, PL to UCS conversion factors of trona and interbeds are proposed.

UCS tests were performed using NX-size (54 mm) core samples of quartzite, sandstone, amphibolite, gabbro, khondalite, epidiorite, limestone, dolomite, …

But as the ratio of (mean UCS/mean PLT) increases the k factor increased linearly as the equation, k=0.871(mean UCS/mean PLT), which is a new derived equation easily can be used and must be the ...

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 …

(PLT), which is a simple and widely accepted testing ... Conversion factors between UCS and PLA for Limestone rocks Study Country PLA to UCS conversion factor Hawkins and Olver (1986) UK 26.5 ...

ISRM (1985) has given conversion factors of 20 and 25 between PLI and UCS. Broch and Franklin (1972) pro-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 …

The index-to-strength conversion factor was computed as the ratio of UCS over PLT index from the design line. To establish the relationship between PLT index …

From the results of these tests, a conversion factor equal to 14 is proposed to correct the point load strength index in order to estimate the uniaxial compressive …

Uniaxial Compressive Strength (UCS) is one of the most important properties of rocks. Point Load Test (PLT) is practically used in geotechnical engineering to determine rock strength index. Despite that the PLT is fast, economical and simple in either field or laboratory, Uniaxial Compressive Test (UCT) is time-consuming and expensive.

estimation of UCS. The correlation factors vary widely depending upon the rock type, weathering grades, mineralogical formations and stratigraphic structures and number of test results being correlated. Therefore, for a reasonable and valid estimation of UCS from simple tests, calculation of the correlation factor on reasonable

Uniaxial compression strength (UCS) is a fundamental parameter to carry out geotechnical engineering design and construction. It is simple and efficient to predict UCS using point load strength (PLS) at engineering sites. However, the high dispersion of rock strength limits the accuracy of traditional fitting prediction methods. In order to improve …

The implementation has been conducted over 700 field and laboratory tests of which 255 are PLT test, 45 are UCS test, and the rest are other parameters like: porosity and specific weight, Slake ...

estimate UCS of various rocks through developing simple correlations among the results of uniaxial compressive strength (UCS) and indirect tests on the

The correlation obtained between UCS and PLT is strong (r = 0.85) (Fig. 21a), similar to the result by other authors [154, 155, 177,178]. In the literature consulted the linear fit is the most ...

ratio, which is termed the strength conversion factor (k). Broch and Franklin (1972) indicated that the UCS was approximately 24 times the PLI for a standard-size (50-mm) core. Bieniawski (1975) showed that the UCS was nearly 23 times the PLI. Pells (1975) stated that using an index to strength conversion factor of 24 yielded a 20 %

The strength conversion factor (k) is the ratio between the uniaxial compressive strength (UCS) and the point load index (PLI). It has been used to estimate the UCS from the PLI since the 1960s. Many researchers have investigated the relationship between UCS and PLI for various rock types of different geological origins, such as …