Lu, R., Luo, Q., Wang, T. et al. (3 more authors) (2023) Discrete element modelling of the effect of aspect ratio on compaction and shear behaviour of aggregates. Computers and Geotechnics, 161. 105558. ISSN 0266-352X
Abstract
Coarse aggregates are essential for constructing railways and highways, as they affect structural performance through their compacted state and shear strength. Particle geometry influences these properties, but little research has quantitatively investigated how shape indexes impact mechanical indicators. This study addresses this gap by exploring the effect of particle aspect ratio on coarse aggregate compaction and shear behavior using the discrete element method (DEM). The study's key contribution is the development of novel equations that describe the correlation between packing porosity, inter-particle contact state, and aspect ratio control thresholds in a practical format. To do so, first, a point cloud database is compiled from laser scans of 700 natural aggregate particles. Each particle is classified using three aspect-ratio parameters: elongation, flatness, and flatness-elongation index (FEI). They are then digitized as rigid block particle models and compared against actual point clouds. Next, nine aggregates of representative shapes are assessed for their macro and mesoscopic mechanical responses using DEM-based vibro-compaction and direct shear tests. The compaction simulations indicate an exponential relationship between porosity and inter-particle coefficient of friction and show that aggregates with FEI ≈ 0.5 are a good choice. The direct shear simulations consider the same initial porosity, and show that the relationship between peak shear strength and vertical stress follows a power function. Finally, the analysis of contact forces and fabric tensors implies that FEI ≈ 0.5 may also facilitate particle fragmentation control.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 Elsevier Ltd. All rights reserved. This is an author produced version of an article published in Computers and Geotechnics made available under the CC-BY-NC-ND 4.0 license (http://creativecommons.org/licenses/by-nc-nd/4.0) in accordance with the publisher's self-archiving policy. |
Keywords: | Granular aggregates; Aspect ratio; Railway-highway; Discrete element method; Rigid block; Laser scanning |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Funding Information: | Funder Grant number Royal Society IEC|NSFC|211306 |
Depositing User: | Symplectic Publications |
Date Deposited: | 24 Jul 2023 11:18 |
Last Modified: | 03 Jun 2024 00:13 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.compgeo.2023.105558 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:201802 |