Investigation of the availability of a new point load test device in characterization of rocks

Abstract

Difficulties in determining rock properties have led to the developed and increased use of index test methods predicting them. Index test methods are mostly simple, cheap, and easy to apply but there are some restrictions due to these specifications. The most used method to determine the strength values of rocks indirectly is the point load index. The main aim of this study is primarily investigating the usability of modified test device instead of classical test device. For this, laboratory tests were carried out on rocks with different strength values (3 igneous, 1 metamorphic, 3 sedimentary). The point load index tests were carried on 15 different classical test devices and on a modified test device which the limitations of the classical test device were eliminated. Analysis of the obtained results was carried out by the simple regression method. It was determined the modified test device can be used reliably instead of the classical test devices. Besides, while determining the strength tests the stress distributions on the samples were examined with the finite element method.

Keywords

• Natural stone
• Point load index
• Rock characterization
• Test device

References

1. 1 Akbay, D., Designing A New Testing Apparatus For Preventing The Errors in Point Load Index Test, in: Mining Engineering 2018, Süleyman Demirel University: Turkey. p. 201.
2. 2 Andrea, D.V.D., R.L. Fischer, and D.E. Fogelson, Prediction of Compressive Strength From Other Rock Properties. 1965, USA: Department of the Interior, Bureau of Mines.
3. 3 Broch, E. and J. A. Franklin, The Point-Load Strength Test. International Journal of Rock Mechanics and Mining Sciences, 1972. 9: p. 669–697.
4. 4 Bieniawski, Z.T., The point-load test in geotechnical practice. Engineering Geology, 1975. 9(1): p. 1–11.
5. 5 Singh, V.K. and D.P. Singh, Correlation between point load index and compressive strength for quartzite rocks. Geotechnical and Geological Engineering, 1993. 11(4): p. 269–272.
6. 6 Rusnak, J. and C. Mark, Using the Point Load Test To Determine the Uniaxial Compressive Strength of Coal Measure Rock. in Proceedings of the 19th International Conference on Ground Control in Mining, Morgantown, West Virginia., 2000. p. 362–371.
7. 7 Akram, M. and M.Z.A. Bakar, Correlation between uniaxial compressive strength and point load index for salt-range rocks. Pakistan Journal of Engineering and Applied Sciences, 2007. 1(50): p. 1–8.
8. 8 Basu, A. and M. Kamran, Point load test on schistose rocks and its applicability in predicting uniaxial compressive strength. International Journal of Rock Mechanics and Mining Sciences, 2010. 47(5): p. 823–828.

9. 9 Heidari, M., G.R. Khanlari, M.T. Kaveh, and S. Kargarian, Predicting the uniaxial compressive and tensile strengths of gypsum rock by point load testing. Rock Mechanics and Rock Engineering, 2012. 45(2): p. 265–273.
10. 10 Singh, T.N., A. Kainthola, and A. Venkatesh, Correlation between point load index and uniaxial compressive strength for different rock types. Rock Mechanics and Rock Engineering, 2012. 45(2): p. 259–264.
11. 11 Elhakim, A.F., The use of point load test for Dubai weak calcareous sandstones. Journal of Rock Mechanics and Geotechnical Engineering, 2015. 7(4): p. 452–457.
12. 12 Liang, W., K. Hou, Z. Yang, and H. Sun, Evaluation of Uniaxial Compressive Strength by Point Load Tests for Irregular Specimens of Different Rock Types. Electronic Journal of Geotechnical Engineering, 2015. 20(13):, p. 11265–11271.
13. 13 Alitalesh, M., M. Mollaali, and M. Yazdani, Correlation between uniaxial strength and point load index of rocks. in The 15th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, Fukuoka, Kyushu, Japan, 2015. p. 282–285.
14. 14 Wong, R.H.C., K.T. Chau, J.H. Yin, D.T.W. Lai, and G.S. Zhao, Uniaxial compressive strength and point load index of volcanic irregular lumps. International Journal of Rock Mechanics and Mining Sciences, 2017. 93(February): p. 307–315.
15. 15 Akbay, D. and R. Altindag, Reliability and evaluation of point load index values obtained from different testing devices. The Southern African Institute of Mining and Metallurgy, 2020. 120(3): p. 181–190.
16. 16 Al-Jassar, S.H. and A.B. Hawkins, Geotechnical Properties of The Carboniferous Limestone of The Bristol Area The Influence of Petrography And Chemistry. in 4th ISRM Congress, Montreux, Switzerland, 1979. p. 3–14.
17. 17 Çobanoǧlu, I. and S.B. Çelik, Estimation of uniaxial compressive strength from point load strength, Schmidt hardness and P-wave velocity. Bulletin of Engineering Geology and the Environment, 2008. 67(4): p. 491–498.
18. 18 Minaeian, B. and K. Ahangari, Prediction of the uniaxial compressive strength and Brazilian tensile strength of weak conglomerate. International Journal of Geo-Engineering, 2017. 8(1): 19, p. 1-11.
19. 19 Ferentinou, M. and M. Fakir, An ANN Approach for the Prediction of Uniaxial Compressive Strength, of Some Sedimentary and Igneous Rocks in Eastern KwaZulu-Natal. Procedia Engineering, 2017. 191: p. 1117–1125.
20. 20 Teymen, A., Prediction of Basic Mechanical Properties of Tuffs Using Physical and Index Tests. Journal of Mining Science, 2018. 54(5): p. 721–733.
21. 21 Khajevand, R. and D. Fereidooni, Utilization of the point load and block punch strengths to predict the mechanical properties of several rock samples using regression analysis methods. Innovative Infrastructure Solutions, 2019. 4: p. 15.
22. 22 Brook, N., Size Correction for Point Load Testing. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1980. 17( 2): p. 231–235.
23. 23 Abbs, A.F., The Use of the Point Load Index in Weak Carbonate Rocks. in ASTM STP 883, R. C. Chaney and K. R. Demars, Eds., American Society for Testing and Materials, Philadelpliia, 1985. p. 413–421.
24. 24 Norbury, D.R., The Point Load Test. Engineering Geology Special Publication, 1986. 2: pp. 326–329.
25. 25 Hawkins, A.B., Aspects of rock strength. Bulletin of Engineering Geology and the Environment, 1998. 57(1): p. 17–30.
26. 26 Khanlari, G., B. Rafiei, and Y. Abdilor, Evaluation of strength anisotropy and failure modes of laminated sandstones. Arabian Journal of Geosciences, 2014. 8: p. 3089–3102.
27. 27 Smith, H.J., The Point Test for Weak Rock in Dredging Applications. International Journal of Rock Mechanics and Mining Sciences., 1997. 34(295): p. 3–4.
28. 28 Look, B.G. and S.G. Griffiths, An Engineering Assessment of the Strength and Deformation Properties of Brisbane Rocks. Australian Geomechanics Journal, 2001. 36(3): p. 17–30.
29. 29 Quane, S.L. and J.K. Russell, Ranking welding intensity in pyroclastic deposits. European Journal of Mineralogy, 2003. 15: p. 855–864.
30. 30 Basu, A. and A. Aydin, Predicting uniaxial compressive strength by point load test: Significance of cone penetration. Rock Mechanics and Rock Engineering, 2006. 39(5): p. 483–490.
31. 31 Kabilan, N., M. Muttharam, and V. Elamathi, Prediction of Unconfined Compressive Strength for Jointed Rocks Using Point Load Index Based on Joint Asperity Angle. Geotechnical and Geological Engineering, 2017. 35: p. 2625–2636.
32. 32 Ren, F., H. Liu, R. He, G. Li, and Y. Liu, Point load test of half-cylinder core using the numerical model and laboratory tests: Size suggestion and correlation with cylinder core. Advances in Civil Engineering, 2018. 2018(Special Issue): p. 1-11.
33. 33 Mesutoğlu M., İ. Özkan, Büyük ölçekli kömür arınında gerçekleştirilen schmidt sertlik indeksi ve nokta yükleme dayanımı deney sonuçlarının değerlendirilmesi. Konya Journal of Engineering Sciences, 2019. 7: p. 681–695.
34. 34 Guevara-Lopez F., R. Jimenez, P. Gardoni, P. Asem, Probabilistic prediction of intact rock strength using point load tests using a Bayesian formulation. Georisk, 2020. 14(3): p. 206–215.
35. 35 Jamshidi A., Y. Abdi, and R. Sarikhani, Prediction of Brittleness Indices of Sandstones Using a Novel Physico-Mechanical Parameter. Geotechnical and Geological Engineering 2020. 38: p. 1–9.
36. 36 Şahin M., R. Ulusay, and H. Karakul, Point Load Strength Index of Half-Cut Core Specimens and Correlation with Uniaxial Compressive Strength. Rock Mechanics and Rock Engineering, 2020. 53: p 3745–3760.
37. 37 TSE, TS EN 1936, Natural stone test methods - Determination of real density and apparent density and of total and open porosity. 2010, Ankara, Türkiye: TSE.
38. 38 TSE, TS EN 13755, Natural stone test methods - Determination of water absorption at atmospheric pressure. 2014, Ankara, Türkiye: TSE.
39. 39 TSE, TS EN 14579, Natural stone test methods - Determination of sound speed propagation. 2006, Ankara, Türkiye: TSE.
40. 40 TSE, TS EN 14157, Natural stone - Determination of the abrasion resistance. 2017, Ankara, Türkiye: TSE.
41. 41 TSE, TS EN 1926, Natural stone test methods - Determination of uniaxial compressive strength. 2013, Ankara, Türkiye: TSE.
42. 42 ISRM, The complete suggested methods for rock characterization, testing and monitoring: 1974–2006. 2007, London, UK: Springer.
43. 43 TSE, TS EN 12372, Natural stone test methods - Determination of flexural strength under concentrated load. 2013, Ankara, Türkiye: TSE.
44. 44 TSE, TS EN 13161, Natural stone test methods - Determination of flexural strength under constant moment. 2014, Ankara, Türkiye: TSE.
45. 45 ISRM, Suggested Method for Determining Point Load Strength. in ISRM, U. R. and H. J.A., Eds., 1985, London, UK: Springer, p. 53–60.
46. 46 Mavko, G., T. Mukerji, and J. Dvorkin, The Rock Physics Handbook. 2009, Cambridge, UK: Cambridge University Press.