Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM)
Abstract
In geotechnical engineering, shear strength is a fundamental parameter for the design of structures such as dams, foundations, retaining walls, and tunnels. Traditionally, shear strength, which is a function of the internal friction angle and cohesion, is determined through laboratory and field tests. However, with advances in computing, the Discrete Element Method (DEM) has emerged as an effective alternative for modelling and defining these parameters. This study used DEM to model the shear strength of granular soil. The simulation replicated a cylindrical direct shear box test with a radius of 52 mm and a height of 75 mm, applying normal stresses of 12.5, 25, and 50 kPa. The results were then compared to corresponding laboratory tests. The research distinguished itself by focusing on three critical aspects of DEM modelling. First, it aimed to determine the optimum number of sand particles by examining how particle count interacts with density and shear strength. Second, it explored the influence of shear rate on shear strength parameters. Lastly, the study evaluated the impact of contact friction properties—specifically static friction, rolling friction, and restitution coefficients—on the overall shear behaviour.
The findings demonstrate a clear relationship between the tested variables and the internal friction angle. Increasing the shear rate from 0.5 mm/sec to 1 mm/sec and then to 2 mm/sec raised the internal friction angle by 9% and 11%, respectively. Similarly, a rise in the number of particles from 40,000 to 42,500 and then to 45,000 resulted in a 3.2% and 4.67% increase in the internal friction angle, though this was found to affect the accuracy of the results. The study also concluded that optimal shear behaviour in granular soils is achieved with moderate values for static friction (0.5–0.75), rolling friction (0.5–0.6), and restitution (0.05–0.06) coefficients, underscoring the vital importance of accurately calibrating these parameters to reflect real-world conditions.
Keywords
- Granular soil
- Discrete Element Method
- Mechanical behaviour
- Particle interactions
- Direct shear Test (DST)
Ethical Statement
The authors declare that this study complies with research and publication ethics. This study does not require an ethics committee approval as it does not involve any human or animal subjects, surveys, or clinical data. Furthermore, there is no conflict of interest between the authors.
References
- N. R. MacDonald, T. R. M. Packulak, and J. J. Day, “A critical review of current states of practice in direct shear testing of unfilled rock fractures focused on multi-stage and boundary conditions,” Geosciences, vol. 13, 2023, Art. no. 172. doi: 10.3390/geosciences13060172.
- J. M. Audibert and J. Huang, “Geophysical and geotechnical design,” in Handbook of Offshore Engineering, S. K. Chakrabarti, Ed. Amsterdam, Netherlands: Elsevier, 2005, pp. 1145–1268. doi: 10.1016/B978-0-08-044381-2.50023-0.
- A. Cerato and A. Lutenegger, “Specimen size and scale effects of direct shear box tests of sands,” Geotechnical Testing Journal, vol. 29, 2006, pp. 507–516. doi: 10.1520/GTJ100312.
- G. Wang, X. Zhang, X. Liu, Y. Xu, and R. An, “Diatom-induced impact on shear strength characteristics of fine-grained soils,” Journal of Rock Mechanics and Geotechnical Engineering, 2024. doi: 10.1016/j.jrmge.2023.11.042.
- A. Ciancimino, R. M. Cosentini, S. Foti, A. Messori, H. Ullah, G. Volonté, and G. Musso, “A preliminary investigation on the mechanical behaviour of a stiff Italian clay in the context of hydrogen storage,” Geomechanics for Energy and the Environment, vol. 38, 2024, Art. no. 100562. doi: 10.1016/j.gete.2024.100562.
- K. Thermann, C. Gau, and J. Tiedemann, “Shear strength parameters from direct shear tests – influencing factors and their significance,” Proceedings of the IAEG2006 Conference, Geological Society of London, Paper No. 484, 2006. Available: https://www.researchgate.net/publication/237718044
- J. Stacho and M. Sulovska, “Shear strength properties of coarse-grained soils determined using large-size direct shear test,” Civil and Environmental Engineering, vol. 18, no. 1, pp. 244–257, 2022. doi: 10.2478/cee-2022-0023.
- R. Abhishek and S. Chawla, “Large-scale direct shear and discrete element modelling investigations of ballast, sub-ballast, and sleeper interface characteristics in a railway track structure,” in Proc. Indian Geotechnical Conference (IGC 2022), Kochi, India, Dec. 2022, pp. 237–246. DOI: 10.1007/978-981-97-6172-2_20.
Details
Primary Language
English
Subjects
Civil Geotechnical Engineering, Numerical Modelization in Civil Engineering
Journal Section
Research Article
Publication Date
June 30, 2026
Submission Date
September 20, 2025
Acceptance Date
June 17, 2026
Published in Issue
Year 2026 Volume: 16 Number: 1
APA
Bairoti, M., Pulat, H. F., & Talafha, M. S. (2026). Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM). Bitlis Eren University Journal of Science and Technology, 16(1), 16-31. https://doi.org/10.17678/beuscitech.1788074
AMA
1.Bairoti M, Pulat HF, Talafha MS. Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM). Bitlis Eren University Journal of Science and Technology. 2026;16(1):16-31. doi:10.17678/beuscitech.1788074
Chicago
Bairoti, Mohammad, Hasan Fırat Pulat, and Muath S. Talafha. 2026. “Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM)”. Bitlis Eren University Journal of Science and Technology 16 (1): 16-31. https://doi.org/10.17678/beuscitech.1788074.
EndNote
Bairoti M, Pulat HF, Talafha MS (June 1, 2026) Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM). Bitlis Eren University Journal of Science and Technology 16 1 16–31.
IEEE
[1]M. Bairoti, H. F. Pulat, and M. S. Talafha, “Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM)”, Bitlis Eren University Journal of Science and Technology, vol. 16, no. 1, pp. 16–31, June 2026, doi: 10.17678/beuscitech.1788074.
ISNAD
Bairoti, Mohammad - Pulat, Hasan Fırat - Talafha, Muath S. “Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM)”. Bitlis Eren University Journal of Science and Technology 16/1 (June 1, 2026): 16-31. https://doi.org/10.17678/beuscitech.1788074.
JAMA
1.Bairoti M, Pulat HF, Talafha MS. Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM). Bitlis Eren University Journal of Science and Technology. 2026;16:16–31.
MLA
Bairoti, Mohammad, et al. “Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM)”. Bitlis Eren University Journal of Science and Technology, vol. 16, no. 1, June 2026, pp. 16-31, doi:10.17678/beuscitech.1788074.
Vancouver
1.Mohammad Bairoti, Hasan Fırat Pulat, Muath S. Talafha. Geotechnical Evaluation of the Effects of Contact Parameters on the Mechanical Behaviour of Granular Soil Using the Discrete Element Method (DEM). Bitlis Eren University Journal of Science and Technology. 2026 Jun. 1;16(1):16-31. doi:10.17678/beuscitech.1788074