Hydromechanical behavior of unsaturated sandy soils with different particle shapes under loading–unloading paths: Numerical simulation and experimental validation
[en] This study investigates the simultaneous influence of particle shape and initial suction on the hydromechanical behavior of unsaturated sandy soils. Anisotropic loading–unloading tests at constant water content conditions were conducted on three sands with distinct shapes (Firoozkooh – most angular, Babolsar – Subangular, and Mesr – roundest) using a direct shear apparatus. Particle shapes were quantified in terms of sphericity, roundness, and regularity using the results of scanning electron microscopy (SEM) tests. In addition, a coupled hydromechanical model based on elasto-viscoplasticity was developed and validated against the experimental results first. The model was then employed to conduct a parametric study (compressibility, pore water pressure, and permeability) with an emphasis on the role of particle morphology and shape. The findings revealed rounder particles (higher regularity) experienced higher volumetric strain (εv) under lower suction but less εv with increasing suction compared to angular sands. Moreover, the rate of permeability reduction during loading in Mesr sand was 1.5 times and 2.4 times higher than that of Babolsar and Firoozkooh sands at near-saturation condition. However, this amount decreased with increasing suction. Pore water pressure (PWP) generation was highest in the most angular sand due to its retention characteristics. The relationship between void ratio and PWP was independent of loading cycles and exhibited a linear dependence. Particle shape significantly impacted this relationship, with rounder sands showing a higher rate of void ratio change per unit change in PWP.
Disciplines :
Civil engineering
Author, co-author :
MOUSAVI AVINDIN, Zahra Alsadat ; University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Engineering (DoE)
JABBARZADEH GHANDILOU, Milad ; University of Luxembourg > Faculty of Science, Technology and Medicine (FSTM) > Department of Engineering (DoE)
Jafarzadeh, Fardin; Department of Civil Engineering, Sharif University of Technology, Tehran, Iraq
Sadeghi, Hamed; Department of Civil Engineering, Sharif University of Technology, Tehran, Iraq
External co-authors :
yes
Language :
English
Title :
Hydromechanical behavior of unsaturated sandy soils with different particle shapes under loading–unloading paths: Numerical simulation and experimental validation
The financial support provided by the Research Grant Office at Sharif University of Technology by way of grants G4010902 and QB020105 is gratefully acknowledged.
Abbireddy, C.O.R., Clayton, C.R.I., The impact of particle form on the packing and shear behaviour of some granular materials: an experimental study. Granul Matter 17 (2015), 427–438, 10.1007/s10035-015-0566-0.
Ahmadinezhad, A., Jafarzadeh, F., Shahbodagh, B., Hosseinpour, S., Khorami, S., Development of a dynamic hollow cylinder apparatus for investigating the cyclic response of unsaturated soils subjected to stress anisotropy. Transp Geotech, 40, 2023, 100968, 10.1016/j.trgeo.2023.100968.
Alonso, E.E., Gens, A., Josa, A., A constitutive model for partially saturated soils. Géotechnique 40:3 (1990), 405–430, 10.1680/geot.1990.40.3.405.
Aloufi, M., Santamarina, J.C., Low and high strain macrobehavior of grain masses—the effect of particle eccentricity. Transactions of the ASAE 38:3 (1995), 877–887 https://doi.org/10.13031/2013.27904.
Alshibli, K.A., Cil, M.B., Influence of particle morphology on the friction and dilatancy of sand. J Geotech Geoenviron Eng, 144(3), 2018, 04017118, 10.1061/(ASCE)GT.1943-5606.0001841.
Ameratunga, J., Sivakugan, N., Das, B.M., Correlations of soil and rock properties in geotechnical engineering, 2016, 10.1007/978-81-322-2629-1.
Asadi, R., Mirghasemi, A.A., Numerical investigation of particle shape on mechanical behaviour of unsaturated granular soils using elliptical particles. Adv Powder Technol 29:12 (2018), 3087–3099, 10.1016/j.apt.2018.08.018.
Ashmawy, A.K., Hoang, V.V., Sukumaran, B., May. Evaluating the influence of particle shape on liquefaction behavior using discrete element modeling. In ISOPE International Ocean and Polar Engineering Conference, 2003.
Baghbani, A., Costa, S., Lu, Y., Soltani, A., Abuel-Naga, H., Samui, P., Effects of particle shape on shear modulus of sand using dynamic simple shear testing. Arab J Geosci, 16(7), 2023, 422, 10.1007/s12517-023-11524-9.
Chapuis, R.P., Predicting the saturated hydraulic conductivity of sand and gravel using effective diameter and void ratio. Can Geotech J 41:5 (2004), 787–795, 10.1139/t04-022.
Chen, J., Indraratna, B., Vinod, J.S., Ngo, T., Liu, Y., Discrete element modelling of the effects of particle angularity on the deformation and degradation behaviour of railway ballast. Transp Geotech, 43, 2023, 101154, 10.1016/j.trgeo.2023.101154.
Cho, G., Dodds, J., Santamarina, J., Particle shape effects on packing density, stiffness, and strength: Natural and crushed sands. J Geotech Geoenviron Eng 5:591 (2006), 591–602, 10.1061/(ASCE)1090-0241(2006)132.
Cox, M.R.B., The Influence of Grain Shape on Dilatancy. Dissertations and Theses, 2008 -Gradworks.https://search.proquest.com/openview/849484fb7b6c7d6844f3d58f31f5011d/1?pq-origsite=gscholar&cbl=18750.
Danesh, A., Mirghasemi, A.A., Palassi, M., Evaluation of particle shape on direct shear mechanical behavior of ballast assembly using discrete element method (DEM). Transp Geotech, 23, 2020.
Desai, C.S., Zhang, D., Viscoplastic model for geologic materials with generalized flow rule. Int J Numer Anal Meth Geomech 11:6 (1987), 603–620, 10.1002/nag.1610110606.
Ganju, E., Kılıç, M., Prezzi, M., Salgado, R., Parab, N., Chen, W., Effect of particle characteristics on the evolution of particle size, particle morphology, and fabric of sands loaded under uniaxial compression. Acta Geotech 16:11 (2021), 3489–3516, 10.1007/s11440-021-01309-3.
Gens, A., Olivella, S., THM phenomena in saturated and unsaturated porous media: Fundamentals and formulation. Revue française de génie civil 5:6 (2001), 693–717, 10.1080/12795119.2001.9692323.
Gong, J., Pang, X., Tang, Y., Liu, M., Jiang, J., Ou, X., Effects of particle shape, physical properties and particle size distribution on the small-strain stiffness of granular materials: A DEM study. Comput Geotech, 165, 2024, 105903, 10.1016/j.compgeo.2023.105903.
Griffiths, D.V., Huang, J., Fenton, G.A., Influence of spatial variability on slope reliability using 2-D random fields. J Geotech Geoenviron Eng 135:10 (2009), 1367–1378, 10.1061/(ASCE)GT.1943-5606.0000099.
Ishihara, K. ed., 1995. Earthquake geotechnical engineering. AA Balkema.
Jafarzadeh, F., Sadeghi, H., Experimental study on dynamic properties of sand with emphasis on the degree of saturation. Soil Dyn Earthq Eng 32:1 (2012), 26–41, 10.1016/j.soildyn.2011.08.003.
Khosravi, A., Shahbazan, P., Pak, A., Impact of hydraulic hysteresis on the small strain shear modulus of unsaturated sand. Soils Found 58:2 (2018), 344–354, 10.1016/j.sandf.2018.02.018.
Kohgo, Y., Nakano, M., Miyazaki, T., Theoretical aspects of constitutive modelling for unsaturated soils. Soils Found 33:4 (1993), 49–63, 10.3208/sandf1972.33.4_49.
Kolahdooz, A., Sadeghi, H. and Ahmadi, M.M., 2020. A numerical study on the effect of salinity on stability of an unsaturated railway embankment under rainfall. In E3S Web of Conferences (Vol. 195, p. 01004). EDP Sciences. https://doi.org/10.1051/e3sconf/202019501004.
Kozicki, J., Tejchman, J., Mróz, Z., Effect of grain roughness on strength, volume changes, elastic and dissipated energies during quasi-static homogeneous triaxial compression using DEM. Granul Matter 14 (2012), 457–468, 10.1007/s10035-012-0352-1.
Krumbein, W.C., Sloss, L.L., Stratigraphy and sedimentation. 2nd Ed., 1963, Freeman and Company, San Francisco.
Lashkari, A., Yaghtin, M.S., Sand flow liquefaction instability under shear–volume coupled strain paths. Géotechnique 68:11 (2018), 1002–1024, 10.1680/jgeot.17.P.164.
Li, L., Dai, Z., Liu, R., Jian, F., Experimental study on the coefficient of earth pressure at rest for sand. Buildings, 13(5), 2023, 1276, 10.3390/buildings13051276.
Liu, B., Lehane, B.M., Xue, J., A one–dimensional elasto-viscoplastic macro-element model for creep analysis of shallow foundations on sand. Comput Geotech, 142, 2022, 104561, 10.1016/j.compgeo.2021.104561.
Liu, P., Chen, R.P., Kang, X., Lei, H., Effects of particle morphology on pore structure and SWRC of granular soils. Géotechnique Letters 13:1 (2023), 29–34, 10.1680/jgele.22.00060.
Liu, X., Zou, D., Liu, J., Zheng, B., Zhou, C., Bai, J., A gradation-dependent particle shape factor for characterizing small-strain shear modulus of sand-gravel mixtures. Transp Geotech, 28, 2021, 100548, 10.1016/j.trgeo.2021.100548.
Lu, Z., Yao, A., Su, A., Ren, X., Liu, Q., Dong, S., Re-recognizing the impact of particle shape on physical and mechanical properties of sandy soils: a numerical study. Eng Geol 253 (2019), 36–46, 10.1016/j.enggeo.2019.03.011.
Marcelo Sánchez. 1997. Implementation of VP model by Desai in CB. Used to simulate triaxial tests under drained conditions. Master's Thesis, UPC, 1997.
Matsumura, Y., Jenne, D., Jackson, T.L., Numerical simulation of fluid flow through random packs of ellipses. Phys Fluids, 27(2), 2015, 10.1063/1.4907409.
Molist Jordi. 1997. Extension of the VP model by Desai to unsaturated soils. Graduation Thesis. UPC. 1997.
Mousavi, Z., Jabbarzadeh, M., 3D DEM-based analysis of cylindrical rock specimen failure and micro-fracturing: impact of stiffness and tensile strength. Discover Geoscience, 21, 2025, 10.1007/s44288-025-00126-5.
Mu, Q.Y., Dai, B.L., Zhou, C., A constitutive model for structured soils under saturated and unsaturated conditions. Int J Numer Anal Meth Geomech 47:14 (2023), 2562–2586, 10.1002/nag.3592.
Mualem, Y., A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12:3 (1976), 513–522, 10.1029/WR012i003p00513.
Namjoo, A.M., Baniasadi, M., Jafari, K., Salam, S., Toufigh, M.M., Toufigh, V., Studying effects of interface surface roughness, mean particle size, and particle shape on the shear behavior of sand-coated CFRP interface. Transp Geotech, 37, 2022, 100841, 10.1016/j.trgeo.2022.100841.
Necochea, J.E., Sáez, E., Hanley, K.J., Effect of sand particle shape on micromechanical modeling in direct shear testing. Comput Geotech, 169, 2024, 106222, 10.1016/j.compgeo.2024.106222.
Ng, C.W.W., Baghbanrezvan, S., Sadeghi, H., Zhou, C. and Jafarzadeh, F., 2017. Effect of specimen preparation techniques on dynamic properties of unsaturated fine-grained soil at high suctions. Canadian Geotechnical Journal, 54(9), pp.1310-1319. https://doi.org/10.1139/cgj-2016-0531Ng, C.W.W., Zhou, C. and Chiu, C.F., 2020. Constitutive modelling of state-dependent behaviour of unsaturated soils: an overview. Acta Geotechnica, 15(10), pp.2705-2725. https://doi.org/10.1007/s11440-020-01014-7.
Nguyen, T.T., Indraratna, B., The role of particle shape on hydraulic conductivity of granular soils captured through Kozeny–Carman approach. Géotechnique Letters 10:3 (2020), 398–403, 10.1680/jgele.20.00032.
Nie, J.Y., Cui, Y., Wang, G., Wang, R., Zhang, N., Zhang, L., et al. A comprehensive numerical investigation of multi-scale particle shape effects on small strain stiffness of sands. Géotechnique, 2024, 1–37, 10.1680/jgeot.23.00118.
Nie, J.Y., Shi, X.S., Cui, Y.F., Yang, Z.Y., Numerical evaluation of particle shape effect on small strain properties of granular soils. Eng Geol, 303, 2022, 106652, 10.1016/j.enggeo.2022.106652.
Nimtaj, A., Shokati Beyrag, B., Impact of particle morphology on the friction angle of Firoozkouh Sand. Geotech Geol Eng 41:2 (2023), 1557–1565, 10.1007/s10706-022-02353-w.
Olivella, S., Carrera, J., Gens, A., Alonso, E.E., Nonisothermal multiphase flow of brine and gas through saline media. Transp Porous Media 15 (1994), 271–293, 10.1007/BF00613282.
Olivella, S., Gens, A., Carrera, J., Alonso, E.E., Numerical formulation for a simulator (CODE_BRIGHT) for the coupled analysis of saline media. Eng Comput 13:7 (1996), 87–112, 10.1108/02644409610151575.
Patil, U.D., Hoyos, L.R., Puppala, A.J., Modeling essential elastoplastic features of compacted silty sand via suction-controlled triaxial testing. Int J Geomech, 16(6), 2016, D4016012, 10.1061/(ASCE)GM.1943-5622.0000726.
Payan, M., Senetakis, K., Khoshghalb, A., Khalili, N., Effect of gradation and particle shape on small-strain Young's modulus and Poisson's ratio of sands. Int J Geomech, 17(5), 2017, 04016120, 10.1061/(ASCE)GM.1943-5622.0000811.
Peng, F.L., Siddiquee, M.S.A., Tatsuoka, F., Yasin, S.J.M., Tanaka, T., Strain energy-based elasto-viscoplastic constitutive modelling of sand for numerical simulation. Soils Found 49:4 (2009), 611–629, 10.3208/sandf.49.611.
Perzyna, P., Fundamental problems in viscoplasticity. Adv Appl Mech 9 (1966), 243–377, 10.1016/S0065-2156(08)70009-7.
Qin, Y., Yao, T., Wang, R., Zhu, C.Q., Meng, Q.S., Particle breakage-based analysis of deformation law of calcareous sediments under high-pressure consolidation. Rock Soil Mech 35:11 (2014), 3123–3128 https://doi.org/10.16285/j.rsm.2014.11.009.
Sadeghi, H., A micro-structural study on hydro-mechanical behavior of loess (Doctoral dissertation. 2016, Hong Kong University of Science and Technology).
Sadeghi, H., Heydari, A., Zhou, C., Insights into the fluid retention and shrinkage of a lean clay under the combined influence of microstructure, solute concentration and salt species. Acta Geotech 19:7 (2024), 4855–4872, 10.1007/s11440-023-02206-7.
Santamarina, C., Cascante, G., Effect of surface roughness on wave propagation parameters. Geotechnique 48:1 (1998), 129–136, 10.1680/geot.1998.48.1.129.
Sarkar, D., König, D., Goudarzy, M., The influence of particle characteristics on the index void ratios in granular materials. Particuology 46 (2019), 1–13, 10.1016/j.partic.2018.09.010.
Shafiee, A., Dabiri, R., Askari, F., Dynamic properties of Firoozkooh sand-silt mixtures. Journal of Seismology and Earthquake Engineering 19:4 (2017), 273–284 http://www.jsee.ir/article_240770.html.
Shin, H., Santamarina, J.C., Role of particle angularity on the mechanical behavior of granular mixtures. J Geotech Geoenviron Eng 139:2 (2013), 353–355, 10.1061/(ASCE)GT.1943-5606.0000768.
Sutharsan, T., Muhunthan, B., Liu, Y., Development and implementation of a constitutive model for unsaturated sands. Int J Geomech, 17(11), 2017, 04017103, 10.1061/(ASCE)GM.1943-5622.0001004.
Van Genuchten, M.T., A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci Soc Am J 44:5 (1980), 892–898, 10.2136/sssaj1980.03615995004400050002x.
Xiao, Y., Fang, Q., Stuedlein, A.W., Matthew Evans, T., Effect of particle morphology on strength of glass sands. Int J Geomech, 23(8), 2023, 04023117, 10.1061/IJGNAI.GMENG-8661.
Yang, J., Luo, X.D., Exploring the relationship between critical state and particle shape for granular materials. J Mech Phys Solids 84 (2015), 196–213, 10.1016/j.jmps.2015.08.001.
Yilmaz, Y., Deng, Y., Chang, C.S., Gokce, A., Strength–dilatancy and critical state behaviours of binary mixtures of graded sands influenced by particle size ratio and fines content. Géotechnique 73:3 (2023), 202–217, 10.1680/jgeot.20.P.320.
Ying, M., Liu, F., Wang, J., Wang, C., Li, M., Coupling effects of particle shape and cyclic shear history on shear properties of coarse-grained soil–geogrid interface. Transp Geotech, 27, 2021, 100504, 10.1016/j.trgeo.2020.100504.
Youd, T.L., 1973. Factors controlling maximum and minimum densities of sands. In Evaluation of relative density and its role in geotechnical projects involving cohesionless soils. ASTM International. https://doi.org/10.1520/STP37866Shttps://doi.org/10.1520/STP37866S.
