Effect of Confining Pressure on Is(50) Obtained by Point Load Test | ||
| Journal of Mining and Environment | ||
| مقاله 8، دوره 12، شماره 4، دی 2021، صفحه 1019-1028 اصل مقاله (5.75 M) | ||
| نوع مقاله: Original Research Paper | ||
| شناسه دیجیتال (DOI): 10.22044/jme.2021.10918.2070 | ||
| نویسندگان | ||
| V. Sarfarazi* 1؛ K. Asgari2 | ||
| 1Associate Professor, Department of Mining Engineering, Hamedan University of Technology, Hamedan, Iran | ||
| 2Research Scholar, Department of Mining Engineering, Shahid Bahonar University of Kerman, Kerman, Iran | ||
| چکیده | ||
| In this investigation, the impact of confining pressure on the tensile strength obtained by point load test (PLT) is examined by particle flow code in two dimensions. In this regard, at first, a numerical model is calibrated using the Brazilian experimental test results. The tensile strength of the model material is equal to 2.5 MPa. Secondly, PLT is performed on the numerical models with dimension of 15 cm × 50 cm. The rectangular models are tested by PLT under the presence of the confining pressure. The loading rate is 0.001 mm/min, confining that the pressure is changed with the 13 different values of 0 MPa, 0.002 MPa, 1MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3MPa, 3.5 MPa, 4 MPa, 5MPa, 6 MPa, 9 MPa, and 11 MPa. The results obtained show that the vertical tensile crack develops through the model under a low confining pressure, while several shear bands are developed in the models under a high confining pressure. The number of shear cracks is augmented by augmenting the confining pressure. Is(50) is the augment by augmenting the confining pressure. Also a new criterion is rendered in order to determine Is(50) based on the confining pressure. | ||
| کلیدواژهها | ||
| Point load test؛ PFC2D؛ Tensile crack | ||
| مراجع | ||
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[1]. Bazant, Z.P. (2002). Concrete fracture models: testing and practice. Engineering Fracture Mechanics 69, 165–205.
[2] Shah, SP., Swartz, SE. and Ouyang, C. (1995) Fracture mechanics of concrete. New York: John Willey and Sons Inc.
[3]. Chen, W.F. (1970). Double punch test for tensile strength of concrete. ACI Materials Journal 67 (2): 993–995.
[4]. Mazars, J. (1986). A description of micro- and macroscale damage of concrete structures. Engineering Fracture Mechanics 25, 729–737.
[5]. Protodyakonov, M.M. and Voblikov, V.S. (1957). Determining the strength of rocks on samples of an irregular shape, Ugol. 32 (4).
[6]. Bieniawski, Z.T. (1975). The point-load test in geotechnical practice, Eng. Geol. 9 (1): 1-11.
[7]. Broch, E. and Franklin, J.A. (1972). The point-load strength test, J. Rock Mech. Min. Sci. Geomech. Abstr. 9 (6): 669-676.
[8]. Basu, A. and Kamran, M. (2010). Point load test on schistose rocks and its applicability in predicting uniaxial compressive strength, J. Rock Mech. Min. Sci. 47 (5): 823-828.
[9]. Basu, A., Mishra, D.A., and Roychowdhury, K. (2013). Rock failure modes under uniaxial compression, Brazilian, and point load tests”, Bull. Eng. Geol. Environ. 72 (3, 4): 457-475.
[10]. Singh, T.N., Kainthola, A. and Venkatesh, A. (2012). Correlation between point load index and uniaxial compressive strength for different rock types, Rock Mech. Rock Eng. 45 (2): 259-264.
[11]. Chau, K.T. and Wong, R.H.C. (1996). Uniaxial compressive strength and point load strength of rocks, J. Rock Mech. Min. Sci. Geomech. Abstr. 33 (2): 183-188.
[12]. Fener, M., Kahraman, S., Bilgil, A. and Gunaydin, O. (2005). A comparative evaluation of indirect methods to estimate the compressive strength of rocks, Rock Mech. Rock Eng. 38 (4): 329-343.
[13]. Sonmez, H. and Osman, B. (2008). The limitations of point load index for predicting of strength of rock material and a new approach”, Proceedings of the 61st Geological Congress of Turkey, 1, 261-262.
[14]. Sonmez, H., Gokceoglu, C., Medley, E.W., Tuncay, E. and Nefeslioglu, H.A. (2006). Estimating the uniaxial compressive strength of a volcanic bimrock”, J. Rock Mech. Min. Sci. 43 (4): 554-561.
[15]. Sonmez, H., Tuncay, E. and Gokceoglu, C. (2004). Models to predict the uniaxial compressive strength and the modulus of elasticity for Ankara agglomerate, J. Rock Mech. Min. Sci. 41 (5): 717-729.
[16]. Basu, A. and Aydin, A. (2006). Predicting uniaxial compressive strength by point load test: significance of cone penetration, Rock Mech. Rock Eng. 39 (5): 483-490.
[17]. Kahraman, S. and Gunaydin, O. (2009). Effect of rock classes on the relation between uniaxial compressive strength and point load index, Bull. Eng. Geol. Environ. 68 (3): 345-353.
[18]. Kayabal, K. and Selçuk, L. (2010). Nail penetration test for determining the uniaxial compressive strength of rock, J. Rock. Mech. Min. Sci. 47 (2): 265-271.
[19]. Ma, G.W. and Wu, W. (2010). Water saturation effects on sedimentary rocks, Civil Eng. Res., 23, 129131.
[20]. Heidari, M., Khanlari, G., Torabi Kaveh, M. and Kargarian, S. (2012). Predicting the uniaxial compressive and tensile strengths of gypsum rock by point load testing, Rock Mech. Rock Eng. 45 (2): 265-273.
[21]. Singh, V.K. and Singh, D.P. (1993). Correlation between point load index and compressive strength for quartzite rocks, Geotch. Geol Eng. 11 (4): 269-272.
[22]. Li, D. and Wong, L.N.Y. (2013). Point load test on meta-sedimentary rocks and correlation to UCS and BTS, Rock Mech. Rock Eng. 46 (4): 889-896.
[23]. Haeri, H., Khaloo, A. and Marji, M.F. (2015). Experimental and numerical analysis of Brazilian discs with multiple parallel cracks, Arab. J. Geosci. 8 (8): 5897-5908.
[24]. Haeri, H., Shahriar, K., Marji, M.F. and Moarefvand, P. (2015). The HDD analysis of micro-crack initiation, propagation, and coalescence in brittle substances, Arab. J. Geosci. 8 (5): 2841-2852.
[25]. Tsiambaos, G. and Sabatakakis, N. (2004). Considerations on strength of intact sedimentary rocks, Eng. Geol., 72(3), 261-273.
[26]. Zhou, Y.X., Xia, K., Li, X.B., Li, H.B., Ma, G.W., Zhao, J., Zhou, Z.L. and Dai, F. (2012). Suggested methods for determining the dynamic strength parameters and mode-I fracture toughness of rock materials, J. Rock. Mech. Min. Sci., 49, 105-112.
[27]. Ayatollahi, M.R. and Alborzi, M.J. (2013). Rock fracture toughness testing using SCB specimen, Proceedings of the 13th International Conference on Fracture, Beijing, China, June.
[28]. Wei, M.D., Dai, F., Xu, N.W., Xu, Y. and Xia, K. (2015). Three-dimensional numerical evaluation of the progressive fracture mechanism of cracked chevron notched semi-circular bend rock specimens, Eng. Fract. Mech., 134, 286-303.
[29]. Xu, N.W. Dai, F. Wei, M.D. Xu, Y. and Zhao, T. (2015a). Numerical observation of three dimensional wing-cracking of cracked chevron notched Brazilian disc rock specimen subjected to mixed mode loading”, Rock Mech. Rock Eng. 49 (1): 79-96.
[30]. Lee, S., Lee, S.H. and Chang, Y.S. (2015). Evaluation of RPV according to alternative fracture toughness requirements, Struct. Eng. Mech. 53 (6): 1271-1286.
[31]. Rajabi, M. Soltani, N. and Eshraghi, I. (2016). Effects of temperature dependent material properties on mixed mode crack tip parameters of functionally graded materials, Struct. Eng. Mech. 58 (2): 144-156.
[32]. Yaylaci, M. (2016). The investigation crack problem through numerical analysis, Struct. Eng. Mech. 57 (6): 1143-1156.
[33]. Lin, Q. and Cao, P. (2021). Crack coalescence in rock-like specimens with two dissimilar layers and pre-existing double parallel joints under uniaxial compression, International Journal of Rock Mechanics and Mining Sciences, 139: 39-53.
[34] Lin, Q., Cao, P., Cao, R., Lin, H. and Meng, J. (2020). Mechanical behavior around double circular openings in a jointed rock mass under uniaxial compression, Archives of Civil and Mechanical Engineering. 20 (1):33-45.
[35]. Lin, Q. and Cao P. (2020). Fatigue behavior and constitutive model of yellow sandstone containing pre-existing surface crack under uniaxial cyclic loading, Theoretical and Applied Fracture Mechanics, 109: 111-128.
[36]. Lin, Q. and Cao P. (2020). Strength and failure characteristics of jointed rock mass with double circular holes under uniaxial compression: Insights from discrete element method modelling, Theoretical and Applied Fracture Mechanics, 109: 77-89.
[37]. Lin, Q. and Cao, P. (2021). Mechanical behavior of a jointed rock mass with a circular hole under compression-shear loading: Experimental and numerical studies, Theoretical and Applied Fracture Mechanics, 114: 100-113.
[38]. Kahraman, S., Gunaydin, O. and Fener, M. (2005). The effect of porosity on the relation between uniaxial compressive strength and point load index, J. Rock. Mech. Min. Sci. 42 (4): 584-589.
[39]. Potyondy, D.O. and Cundall, P.A. (2004). A bonded-particle model for rock. International Journal of Rock Mechanics and Mining Sciences, 41: 1329–1364.
[40]. Palassi, F. and Afzali, M. (2015). Effects of Lateral Confinement on the Results of Point Load Test. Conference: Geohalifax 2009-62nd Canadian Geotechnical Conference At: Halifax, Canada. | ||
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