Geomechanics and Engineering

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Discrete element numerical simulation of dynamic strength characteristics of expanded polystyrene particles in lightweight soil

  • Wei Zhou (College of Water Resources and Architectural Engineering, Northwest A&F University) ;
  • Tian-shun Hou (College of Water Resources and Architectural Engineering, Northwest A&F University) ;
  • Yan Yang (College of Water Resources and Architectural Engineering, Northwest A&F University) ;
  • Yu-xin Niu (College of Water Resources and Architectural Engineering, Northwest A&F University) ;
  • Ya-sheng Luo (College of Water Resources and Architectural Engineering, Northwest A&F University) ;
  • Cheng Yang (Hanjiang to Weihe River Valley Water Diversion Project Construction Co., Ltd.)
  • Received : 2022.09.23
  • Accepted : 2023.07.20
  • Published : 2023.09.10
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Abstract

A dynamic triaxial discrete element numerical model of lightweight soil was established using the discrete element method to study the microscopic mechanism of expanded polystyrene (EPS) particles in the soil under cyclic loading. The microscopic parameters of the discrete element model of the lightweight soil were calibrated depending on the dynamic triaxial test hysteresis curves. Based on the calibration results, the effects of the EPS particles volume ratio and amplitude on the contact force, displacement field, and velocity field of the lightweight soil under different accumulated strains were studied. The results showed that the hysteresis curves of lightweight soil exhibit nonlinearity, hysteresis, and strain accumulation. The strain accumulated in remolded soil is mainly tensile strain, and that in lightweight soil is mainly compressive strain. As the volume ratio of EPS particles increased, the contact force first increased and then decreased, and the displacement and velocity of the particles increased accordingly. With an increase in amplitude, the dynamic stress of the particle system increased, and the accumulation rate of the dynamic strain of the samples also increased. At 5% compressive strain, the contact force of the particles changed significantly and the number of particles deflected in the direction of velocity also increased considerably. These results indicated that the cemented structure of the lightweight soil began to fail at a compressive strain of 5%. Thus, a compressive strain of 5% is more reasonable than the dynamic strength failure standard of lightweight soil.

Keywords

Acknowledgement

Project (51509211) supported by the National Natural Science Foundation of China; Project (2016M602863) supported by China Postdoctoral Science Foundation; Project (2018031) supported by the Excellent Science and Technology Activities Foundation for Returned Overseas Teachers of Shaanxi Province; Project (2015SF260) supported by the Social Development Foundation of Shaanxi Province; Project (2017BSHYDZZ50) supported by the Postdoctoral Science Foundation of Shaanxi Province; Project (2021JLM-51) supported by the Natural Science Foundation of Shaanxi Province; Project (SZ02306) supported by Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University; Project (XKLGUEKF21-02) supported by Xi'an Key Laboratory of Geotechnical and Underground Engineering, Xi'an University of Science and Technology; Project (2452020169) supported by the Fundamental Research Funds for the Central Universities.

References

  1. Anandarajah, A. (1994), "Discrete-element method for simulating behavior of cohesive soil", J. Geotech. Eng., 9(120), 1593-1613. https://doi.org/10.1016/0148-9062(95)99122-E.
  2. Batiste, S., Alshibli, K., Sture, S. and Lankton, M. (2004), "Shear band characterization of triaxial sand specimens using computed tomography", Geotech. Test. J., 27(6), 568-579. https://doi.org/10.1520/GTJ12080.
  3. Bono, D., Mcdowell, G.R. and Wanatowski, D. (2012), "Discrete element modelling of a flexible membrane for triaxial testing of granular material at high pressures", Geotechnique Lett., 2(4), 199-203. https://doi.org/10.1680/geolett.12.00040.
  4. Cundall, P.A. and Strack, O.D.L. (1979), "A discrete numerical model for granular assemblies", Geotechnique, 29(1), 47-65. https://doi.org/10.1680/geot.1979.29.1.47.
  5. Dong, L., Hou, T.S. and Luo, Y.S. (2019), "Dynamic strength parameters of light wright soil mixed with EPS beads", J. Northwest A&F University (Natural Science Edition), 47(5), 139-145. https://doi.org/10.13207/j.cnki.jnwafu.2019.05.018.
  6. Dong, Y. and Fatahi, B. (2020), "Discrete element simulation of cavity expansion in lightly cemented sands considering cementation degradation", Comput. Geotech., 124, https://doi.org/10.1016/j.compgeo.2020.103628.
  7. GB/T50123 (2019), Standard for Soil Test Method, Ministry of Water Resources of People's Republic of China; Beijing, China.
  8. Hou, T.S. (2021), "Influence law of characteristic water content on basic properties of light weight soil", Rock Soil Mech., 33(9), 2581-2587. https://doi.org/10.16285/j.rsm.2012.09.004.
  9. Hou, T.S. and Xu, G.L. (2009), "Experiment on triaxial pore water pressure-stress-strain characteristics of foamed particle light weight soil", China J. Highway Transport, 22(6), 10-17. https://doi.org/10.19721/j.cnki.1001-7372.2009.06.002.
  10. Hou, T.S. and Xu, G.L. (2010), "Experimental study on the shear strength characteristics of foamed particle light weight soil", J. China Univ. Min Tech., 39(4), 534-540. http://www.cnki.com.cn/Article/CJFDTotalZGKD201004011.htm. 1004011.htm
  11. Hou, T.S. and Xu, G.L. (2011), "Influence law of EPS size on shear strength of light weight soil", Chinese J. Geotech. Eng., 33(10), 435-442. http://www.cnki.com.cn/Article/CJFDTotal-YTGC202006026.htm.
  12. Hou, T.S., Xu, G.L. and Lou, J.D. (2011), "Triaxial compression test on shear strength characteristics of light weight sand", J. Central South Univ. (Science and Technology), 42(11), 3521-3529. https://doi.org/10.3969/j.issn.1000-7598.2011.10.016.
  13. Jin, L., Zeng, Y.W., Xia, L. and Ye, Y. (2017), "Experimental and numerical investigation of mechanical behaviors of cemented soil-rock mixture", Geotech. Geol. Eng., 35(1), 337-354. https://doi.org/10.1007/s10706-016-0109-4.
  14. Lan, X., Hou, T.S., Yang, Y. and Zhang, Y.F. (2020), "Discrete element analysis on dynamic deformation characteristics of light weight soil mixed with EPS particles", J. Civil Eng. Management, 37(3), 147-154. https://doi.org/10.3969/j.issn.2095-0985.2020.03.024.
  15. Li, T., Jiang, M.J. and Sun, R.H. (2020), "DEM analysis of evolution law of bond degradation for structured soils", 42(6), 1159-1166. https://d.wanfangdata.com.cn/periodical/ytgcxb202006023.
  16. Lv, X.L., Zeng, S., Li, L.C., Qian, J.G. and Huang, M.S. (2019), "Two-dimensional discrete element simulation of the mechanical behavior and strain localization of anisotropic dense sands", Granular Matter, 21(2), 1-16. https://doi.org/10.1007/s10035-019-0891-9.
  17. Wang, Y.H. and Leung, S.C. (2008), "Characterization of cemented sand by experimental and numerical investigations", J. Geotech. Geoenviron. Eng., 134(7), 992-1004. https://doi.org/10.1061/(ASCE)1090-0241(2008)134:7(992).
  18. Wu, S.C. and Xu, X. (2016), "A study of three intrinsic problems of the classic discrete element method using flat-joint model", Rock Mech. Rock Eng., 49(5), 1813-1830. https://doi.org/10.1007/s00603-015-0890-z.
  19. Xu, W.J., Hu, L.M. and Gao, W. (2016), "Random generation of the meso-structure of a soil-rock mixture and its application in the study of the mechanical behavior in a landslide dam", Int. J. Rock Mech. Min. Sci., 86, 166-178. https://doi.org/10.1016/j.ijrmms.2016.04.007.
  20. Yang, Z.P., Tian, X., Lei, X.D., Jiang, Y.W., Liu, X.R. and Hu, Y.X. (2020), "Particle discrete element numerical study on factors of shear strength characteristics for soil-rock mixture", Eng. Geol., 28(1), 39-50. https://doi.org/10.13544/j.cnki.jeg.2019-285.
  21. Zhang, F.G., Nie, Z.C., Chen, M.F. and Feng, H.P. (2021), "DEM analysis of macro- and micro-mechanical behaviors of cemented sand subjected to undrained cyclic loading", Chinese J. Geotech. Eng., 43(3), 456-464. http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/10.11779/CJGE202103008.
  22. Zhou, Y.D., He, Q.B., Feng, T.G. and Lu, R. (2008), "Comparative researches on dynamic strength properties of lightweight clay-EPS beads soil", J. Hohai Univ. (Natural Sciences), 36(6), 810-813. https://doi.org/10.3876/j.issn.1000-1980.2008.06.018.