آخرین محصولات

Conversion of Point Load Test Results to Conventional

Based on this study, in order to convert PLA to UCS values for rocks such as quartz or sandstone and soft rocks such as shale a conversion factor of 21 to 24 and 14 to 16 …

Point Load Test Results and Conversion Factors

THE UCS AND PLT DATA BASE – DESCRIPTIVE STATISTICS The methodology used in the selection of core samples for testing was as follows: 1. Within each hole, rock units were identified where a sequence of tests had been performed with an identical geologic description and no major gaps in elevation. ... Limestone. he conversion factors (K ...

The estimation of uniaxial compressive strength conversion factor …

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.

Prediction of Uniaxial Compressive Strength (UCS) of …

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

Uni-Axial Compression Strength – Point Load Index …

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

Geosciences | Free Full-Text | The Influence of Pre-Existing

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.

Case study: using the point load test to estimate rock

The limestone core samples simultaneously drilled from side wall have an average conversion factor from PLS to UCS of 24.61. The mean conversion factor from PLS of blocky frag-ments to UCS of limestone in the present study is 40.38. Keywords Pointloadtest .TBMmuck .Blockyfragments . Limestone Introduction

Conversion of Point Load Test Results to Conventional

(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 ...

Rock point load test (PLT index) and its correlation with rock …

As rock UCS is typically adopted for foundation design purpose, the conversion factor between PLT index and UCS was derived for the typical bedrock formation encountered in Kuala Lumpur, namely Granitic rock and Limestone. This study also depicts the estimation of mobilized rock unit shaft friction with respect to the corresponding UCS value ...

400

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 …

USING THE POINT LOAD TEST TO DETERMINE THE UNIAXIAL COMPRESSIVE

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 …

Optimization of UCS testing of limestone rock

Limestone UCS values) with H/D > 1 and typically D <100 mm, correlations need to be established. ... (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. ASTM C170 (1989) addresses rectangular cuboid specimens, h by l by w. A conversion factor

USING THE POINT LOAD TEST TO DETERMINE THE …

appropriate Is50 to UCS conversion factors for different coal measure rocks. The rock strength determined by the PLT, like ... Dredge material various harbors NG 15 UCS<3500 psi sandstone/limestone unk NG 24 UCS>6000 psi Broch and Franklin, 1972 Various UK (?) NG 23.7 11 rock types ... the variability in the PLT-UCS relationship can

The estimation of uniaxial compressive strength conversion factor …

For more details about the conversion factor, the readers can refer to the papers of Kahraman 72 and Ching et al. 75 In the present study, 13 groups of fragments were collected for the PLT to: (1 ...

Utilizing the strength conversion factor in the estimation of …

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 …

(PDF) Correlation Between Point Load Index And …

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 ...

Uniaxial compressive strength measurements of limestone …

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 …

Prediction of Uniaxial Compression Strength of Limestone Based …

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 …

Correlation Between Point Load Index and Uniaxial

Table 2 Conversion factor between UCS and PLI obtained from zero-intercept regression analysis. ... 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, …

A novel equation for calculating uniaxial compressive …

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 mechanics, and it is used to characterize and examine the behaviors of solid rocks. Considering the difficulty of conducting tests on …

Correlation between the point load index (Is(50)) and the …

The PLT uses specimens formed by regular and irregular rock fragments or cylindrical specimens [6, 7] (generally from probes) that are not subjected to strict require-ments to be admissible. This test may take place in situ or in the laboratory. This work presents the most appro-priate values correlating PLT and UCS in limestone from

PLT to UCS correlation factors for various lithologies …

Download scientific diagram | PLT to UCS correlation factors for various lithologies showing the lithology specific nature of the correlation factor. DP is dyke porphyry. from publication: Rock ...

Case study: using the point load test to estimate rock

To use the PLT on blocky fragments to estimate rock strength, it is necessary to find the relation between the point load strength (PLS) of blocky fragments and uniaxial compressive strength (UCS) of surrounding rocks. ... The limestone core samples simultaneously drilled from side wall have an average conversion factor from PLS to …

Equations correlating the UCS to the point load …

Tests easy to perform, as PLT and SHR are also commonly used for indirect determination of UCS. The correlation obtained between UCS and PLT is strong (r = 0.85) (Fig. 21a), similar to the result ...

Empirical relations between rock strength and physical …

between each model's estimated UCS (UCS E) and measured UCS data (UCS M) for a given measured physical property. The obtained values of [UCS E −UCS M] were then used to construct histograms showing a percentage frequency distribution as a function of [UCS E−UCS M]. This was carried out for two ranges of values of each parameter (i.e. low and

CORRELATION BETWEEN UNIAXIAL COMPRESSIVE STRENGTH …

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 ...

Point Load Test | Geoengineer

The UCS can be estimated using the following formula: Where C is a constant that depends on the UCS and I S50 ratio. To correctly derive the value of C both PL and UCS tests must be conducted on the tested material but, if no such data are available, generalized values of C for core samples can be used as shown in Table 1.

Utilizing the strength conversion factor in the …

Utilizing the strength conversion factor in the estimation ... 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. ... It was shown that the average UCS/PLI ratio for three limestone sites was 14.3, which was low compared to the expected ...

Correlation between uniaxial strength and point …

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

A Study on the Correlation between Uniaxial Compressive …

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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