نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه ژئوتکنیک، دانشکده مهندسی عمران و مرکز تحقیقات زلزله دانشگاه صنعتی سهند، تبریز، ایران
2 دانشکده مهندسی عمران و مرکز تحقیقات زلزله دانشگاه صنعتی سهند، تبریز، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Granular materials used today in many engineering projects, such as rockfill dams and railways, have a wide variety of shapes. This shape variation ranges from very sharp to perfectly rounded. The shape of the aggregates affects the mechanical properties of the grain, including fracture strength and internal friction angle. As a result, the mechanical behavior of the mass of granular materials depends on the shape of the grains. In order to investigate the effect of this property, different types of grains in the shapes of spheres, cylinders, cubes and pyramids, which include a wide range of shapes of natural aggregates, were made artificially in size range of 1.5 to 2.0 cm. Small-scale uniaxial compressibility tests were performed on each of the grain shapes under the same conditions including initial porosity ratio and maximum stress and after each experiment, the stress-strain behavior and the amount of breakage were obtained using the Hardin breakage factor. Then, the results were evaluated using an analytical model proposed by McDowell et al. based on the law of conservation of energy. This model has 7 parameters that depend on the initial conditions of the grains, material, shape, size and fracture strength of the grains. Comparison and evaluation of the results indicates the ability of the analytical model to predict the compressibility behavior of pyramidal grains. As the grains become angular, the compressibility and breakage of the materials increase. Also, with increasing the fracture surface energy of the material, the effect of shape on compressibility decreases.
کلیدواژه‌ها [English]
[1] W. Zhou, L. Yang, G. Ma, X. Chang, Z. Lai, K. Xu, DEM analysis of the size effects on the behavior of crushable
granular materials, Granul. Matter, 18(3) (2016) 64.
[2] A. Gupta, Triaxial behaviour of rockfill materials, Electronic Journal of Geotechnical Engineering, 14 (2009).
[3] X. Zhang, B.A. Baudet, T. Yao, The influence of particle shape and mineralogy on the particle strength, breakage and
compressibility, International Journal of Geo-Engineering, 11(1) (2020) 1-10.
[4] P.V. Lade, J.A. Yamamuro, P.A. Bopp, Significance of particle crushing in granular materials, Journal of Geotechnical
Engineering, 122(4) (1996) 309-316.
[5] Y. Wang, S. Shao, Z. Wang, Effect of particle breakage and shape on the mechanical behaviors of granular materials,
Adv. Civil Eng., 2019 (2019) 7248427.
[6] Y. Li, Effects of particle shape and size distribution on the shear strength behavior of composite soils, B. Eng. Geol.
Environ., 72(3) (2013) 371-381.
[7] K. Miura, K. Maeda, M. Furukawa, S. Toki, Mechanical characteristics of sands with different primary properties,
Soils Found., 38(4) (1998) 159-172.
[8] G.-C. Cho, J. Dodds, J.C. Santamarina, Particle shape effects on packing density, stiffness, and strength: natural and
crushed sands, J. Geotech. Geoenviron., 132(5) (2006) 591-602.
[9] N. Altuhafi Fatin, R. Coop Matthew, N. Georgiannou Vasiliki, Effect of particle shape on the mechanical behavior of
natural sands, J. Geotech. Geoenviron., 142(12) (2016) 04016071.
[10] X. Wu, Y. Cai, S. Xu, Y. Zhuang, Q. Wang, Z. Wang, Effects of size and shape on the crushing strength of coral
sand particles under diametral compression test, B. Eng. Geol. Environ., 80(2) (2021) 1829-1839.
[11] T. Zhang, C. Zhang, J. Zou, B. Wang, F. Song, W. Yang, DEM exploration of the effect of particle shape on particle
breakage in granular assemblies, Comput. Geotech., 122 (2020) 103542.
[12] M.B. Cil, C. Sohn, G. Buscarnera, DEM Modeling of Grain Size Effect in Brittle Granular Soils, Journal of
Engineering Mechanics, 146(3) (2020) 04019138.
[13] A.A. Mirghasemi, L. Rothenburg, E.L. Matyas, Influence of particle shape on engineering properties of assemblies
of two-dimensional polygon-shaped particles, Géotechnique, 52(3) (2002) 209-217.
[14] M. Lu, G.R. McDowell, The importance of modelling ballast particle shape in the discrete element method, Granul.
Matter, 9(1) (2007) 69.
[15] S. Abedi, A.A. Mirghasemi, Particle shape consideration in numerical simulation of assemblies of irregularly shaped
particles, Particuology, 9(4) (2011) 387-397.
[16] G.R. McDowell, M.D. Bolton, D. Robertson, The fractal crushing of granular materials, J. Mech. Phys. Solids, 44(12)
(1996) 2079-2101.
[17] Y. Xiao, Y. Sun, H. Liu, F. Yin, Critical state behaviors of a coarse granular soil under generalized stress conditions,
Granul. Matter, 18(2) (2016) 17.
[18] Y. Xiao, Y. Sun, K.F. Hanif, A particle-breakage critical state model for rockfill material, Sci. China Tech. Sci.,
58(7) (2015) 1125-1136.
[19] M. Liu, Y. Gao, H. Liu, An elastoplastic constitutive model for rockfills incorporating energy dissipation of nonlinear
friction and particle breakage, International Journal for Numerical and Analytical Methods in Geomechanics, 38(9)
(2014) 935-960.
[20] A. Daouadji, P.-Y. Hicher, An enhanced constitutive model for crushable granular materials, International Journal
for Numerical and Analytical Methods in Geomechanics, 34(6) (2010) 555-580.
[21] D. Muir Wood, K. Maeda, Changing grading of soil: Effect on critical states, Acta Geotech., 3 (2008) 3-14.
[22] C.S. Chang, P.Y. Hicher, An elasto-plastic model for granular materials with microstructural consideration, Int. J.
Solids Struct., 42(14) (2005) 4258-4277.
[23] W. Salim, B. Indraratna, A new elastoplastic constitutive model for coarse granular aggregates incorporating particle
breakage, Can. Geotech. J., 41(4) (2004) 657-671.
[24] M.-P. Luong, M. Emami, Characterization of mechanical damage in granite, Fracture and Strucrural Integrity, 8(27)
(2014) 38-42.
[25] J. Atkinson, The Mechanics of Soils and Foundations (2nd ed.), CRC Press, 2007.
[26] J. Jaky, Pressure in silos, in: 2nd International Conference on Soil Mechanics and Foundation Engineering, 1948,
[27] J. Zhang, B. Zhang, Fractal pattern of particle crushing of granular geomaterials during one-dimensional
compression, Adv. Civil Eng., (2018) 2153971.
[28] D.L. Turcotte, Fractals and fragmentation, Journal of Geophysical Research: Solid Earth, 91(B2) (1986) 1921-1926.
[29] G.R. McDowell, M.D. Bolton, On the micromechanics of crushable aggregates, Géotechnique, 48(5) (1998) 667-
679.
[30] I. Einav, Breakage mechanics—Part I: Theory, J. Mech. Phys. Solids, 55(6) (2007) 1274-1297.
[31] M.R. Coop, K.K. Sorensen, T. Bodas Freitas, G. Georgoutsos, Particle breakage during shearing of a carbonate sand,
Géotechnique, 54(3) (2004) 157-163.
[32] W. Weibull, A statistical theory of the strength of materials, Generalstabens litografiska anstalts förlag, Stockholm,
1939.
[33] Y. Nakata, Y. Kato, M. Hyodo, A.F.L. Hyde, H. Murata, One-dimensional compression behaviour of uniformly
graded sand related to single particle crushing strength, Soils Found., 41(2) (2001) 39-51.
[34] G. Mesri, B. Vardhanabhuti, Compression of granular materials, Can. Geotech. J., 46(4) (2009) 369-392.
[35] G.R. McDowell, On the yielding and plastic compression of sand, Soils Found., 42(1) (2002) 139-145.
[36] R.D. Holtz, W.D. Kovacs, An Introduction To Geotechnical Engineering, Prentice-Hall, New Jersey, 1981.
[37] A. Sharma, D. Penumadu, Role of particle shape in determining tensile strength and energy release in diametrical
compression of natural silica grains, Soils Found., 60(5) (2020) 1299-1311.
[38] N. Stark, A.E. Hay, R. Cheel, C.B. Lake, The impact of particle shape on the angle of internal friction and the
implications for sediment dynamics at a steep, mixed sand–gravel beach, Earth Surf. Dynam., 2(2) (2014) 469-480.
[39] ASTM-D7012-14e1, Standard Test Methods for Compressive Strength and Elastic Moduli of Intact Rock Core
Specimens under Varying States of Stress and Temperatures, in, ASTM International, West Conshohocken, PA, 2014.
[40] ASTM-D3967-16, Standard Test Method for Splitting Tensile Strength of Intact Rock Core Specimens, in, ASTM
International, West Conshohocken, PA, 2016.
[41] Z.T. Bieniawski, Engineering Rock Mass Classifications: A Complete Manual for Engineers and Geologists in
Mining, Civil, and Petroleum Engineering, Wiley, 1989.
[42] ASTM-D2845-08, Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic
Constants of Rock, in, ASTM International, West Conshohocken, PA, 2008.
[43] V. Hucka, B. Das, Brittleness determination of rocks by different methods, Int. J. Rock Mech. Min., 11(10) (1974)
389-392.
[44] P.J. Barrett, The shape of rock particles, a critical review, Sedimentology, 27(3) (1980) 291-303.
[45] M.C. Powers, A new roundness scale for sedimentary particles, Journal of Sedimentary Research, 23(2) (1953) 117-
119.
[46] ASTM-D2488, Standard practice for description and identification of soils, in, ASTM International, West
Conshohocken, PA, 2017.
[47] B. Indraratna, D. Ionescu, H.D. Christie, Shear behavior of railway ballast based on large-scale triaxial tests, J.
Geotech. Geoenviron., 124(5) (1998) 439-449.
[48] ASTM-D2435, Standard test methods for one-dimensional consolidation properties of soils using incremental
loading, in, ASTM International, West Conshohocken, PA, 2020.
[49] C. Sammis, G. King, R. Biegel, The kinematics of gouge deformation, Pure Appl. Geophys., 125(5) (1987) 777-812.
[50] ASTM-C1444-00, Standard Test Method for Measuring the Angle of Repose of Free-Flowing Mold Powders, in,
ASTM International, West Conshohocken, PA, 2000.
[51] K.L. Lee, I. Farhoomand, Compressibility and crushing of granular soil In anisotropic triaxial compression, Can.
Geotech. J., 4(1) (1967) 68-86.
[52] R. Marsal, Large scale testing of rockfill materials Journal of the Soil Mechanics and Foundations Division, 93(2)
(1967) 27-43.
[53] B.O. Hardin, Crushing of soil particles, Journal of Geotechnical Engineering, 111(10) (1985) 1177-1192.
)