Either three point or four point loading (Fig. 8.6) may be used in the test. For a cylindrical rock specimen (diameter d) and the four point loading arrangement as shown in Fig. 8.6, it may be shown that the tensile strength ( σt) is σt = 32 PL/(3 πd3) (8.2) where P is the failure load applied at each of the third points along the beam.

The point load compression test to irregular lumps was actually proposed before the point load test for rock cores. Protodyakonov (Protodyakonov, 1960) first suggested the idea of testing irregular rock lumps in Russia in 1960. Testing on irregular rock lumps need no sample preparation (such as cutting and grinding).

The Brazilian test is carried out to determine the indirect tensile strength (To) of rocks. The diameter of rock specimens is 60 mm (i.e. D = 60 mm). The diameter to length ratio (D : L) of the rock specimens for the uniaxial compression test, the point load test and the Brazilian test are 1:2.5, 1.1:1 and 2:1, respectively.

Point Load test is an alternate method that can be used to adequately predict the uniaxial compressive strength of a rock material using a portable and simpler equipment. Schmidt Hammer Rebound test is also a technique used for this purpose but, it is admitted that its results are far more variable and affected by testing methods.

The point load test has been considered as a cheap and useful testing method to estimate the strengths of rocks due to its ease of testing, simplicity of specimen preparation, and possible field application (Broch and Franklin 1972; Bieniawski 1975; Kahraman and Gunaydin 2009; Basu and Kamran 2010).It has been often reported as an indirect measure of the compressive or …

The point load test (PLT) is an accepted rock mechanics testing procedure used for the calculation of a rock strength index. This index can be used to estimate other rock strength parameters. The focus of this paper is to present the data analysis used to correlate the point load test index (Is50) with

The UCS, tensile strength and point load index for granite range from 100 to 300 MPa, 7 to 25 MPa, and 5 to 15 MPa respectively. The point load test is intended as an index test for the strength classification of rock materials with which is correlated (Zacoeb and Ishibashi, 2009). In order to

3.7 Criterion 7: Point Load Test Index 7 4. Application of guidelines at piling site involving rock drilling 11 References 12 Appendix 1- Checklist for identification of rocks with weathering grade III or better Appendix 2 - Point load test on irregular rock lumps (template calculation sheet)

3.2 POINT LOAD TEST (PLT) The Point Load Test is also known as the Franklin test. The first reference is by Reichmuth, D. (1968) [10], who proposed obtaining the resistance to a point load and a determination of the unconfined compression strength via correlation, regardless of whether they are irregular, regular, or cylindrical rock controls [11].

The point load test has been gaining acceptance in the field of rock mechanics as a relatively quick and inexpensive field procedure. Advantages claimed are the ability to field test either cores or fragments of rock without preparation, at in-situ moisture ... few igneous rock (granite) cores tested was sufficiently hard to rupture the surface ...

Mark the point to be tested and scanned both side of core. Cutting the core into a different length using cutting machine. Obtained core sample from Gagasan Teguh Company. To determine the effect of length to the corrected point load strength Is (50). To determine the percentage of minerals in granite …

Mark the point to be tested and scanned both side of core. Cutting the core into a different length using cutting machine. Obtained core sample from Gagasan Teguh Company. To determine the effect of length to the corrected point load strength Is (50). To determine the percentage of minerals in granite …

(Figure 8-1). The point load index is used to evaluate the uniaxial compressive strength (F u). On the average, F u. 25 Is(50). However, the coefficient term can vary from 15 to 50 depending upon the specific rock formation, especially for anisotropic rocks. The test should not be used for weak rocks where F u < 25 MPa. Figure 8-1: Point Load ...

2.2 Point Load Testing In order to overcome many of the problems associated with the unconfined compression test, Broch and Franklin (1972) proposed a testing method called the Point Load Test. The test consists of squeezing pieces of rock diametrically between two hardened steel cones. The test set-up is shown in Figure 1.

The present work enriches the literature of point load test, in particular for strong meta-sedimentary rocks. Based on the current study, the following conclusions can be made: 1. The average I s (50) value of the meta-siltstone and the meta-sandstone is …

5.4 Results for maintained load test for Limestone rock 76 5.5 Results for statnamic test using 3 methods and maintained load test (3 rd cycle) for Limestone rock 77 5.6 Results for statnamic test using Unloading Point method for Granite rock 80 5.7 Results for statnamic test using Matsumoto method