| Autor: |
Eshraghi, Hamidreza, Pak, Ali, Motlagh, Nazanin Mahbubi |
| Předmět: |
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| Zdroj: |
Geotechnical & Geological Engineering; Nov2024, Vol. 42 Issue 8, p7979-7998, 20p |
| Abstrakt: |
Simulation of the mechanical behavior of non-cemented and cemented angular limestone material using the discrete element method (DEM) is carried out in the present study and validated by comparison with the experimental triaxial test results. A rolling resistance contact model with spherical particles has been utilized to simulate non-cemented limestone aggregates. Subsequently, relations have been developed to modify two microparameters, the friction coefficient and rolling friction coefficient, representing the surface roughness and the effect of angular corners of aggregates under various confining pressures as a new approach for high-quality simulations. DEM simulations of triaxial tests were then carried out on crushed limestone samples with 1% and 2% cement contents. Flexible lateral boundaries were used in DEM simulations. The increase in cement content usually causes the augmentation of two parameters: cohesion and tensile strength at the contact areas. This paper demonstrates that combining flat joint and newly enhanced rolling resistance contact models provides an effective approach for simulating angular cemented aggregates with spherical shapes. The numerical results agreed well with the experimental results. An increase in cement content in the samples did not alter the distribution of force chains. However, it did increase the intensity of contact forces, resulting in increased shear strength. Moreover, the rise in cement content delayed the rupture of bonds under tension and shear. With increasing the confining pressure, the number of broken cement bonds under tension reduced, while the number of broken bonds under shear increased. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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