All Outputs (10)

Micro-mechanical behavior of stone-blowing in ballast maintenance using DEM-CFD coupling method (2024)
Journal Article
Chen, C., Rao, W., Zhang, L., McDowell, G., & Li, P. (2024). Micro-mechanical behavior of stone-blowing in ballast maintenance using DEM-CFD coupling method. Transportation Geotechnics, 46, Article 101263. https://doi.org/10.1016/j.trgeo.2024.101263

Stone-blowing restores the track geometry by blowing small crushed stones into the bottom of the sleeper, extending the maintenance period. In this study, ballast and filling stones were modelled using discrete element method (DEM), while the air blo... Read More about Micro-mechanical behavior of stone-blowing in ballast maintenance using DEM-CFD coupling method.

A study of membrane correction accounting for both curvature and tension in DEM simulations of triaxial tests of sand and ballast with two alternative flexible membrane models (2024)
Journal Article
Tolomeo, M., & McDowell, G. R. (2024). A study of membrane correction accounting for both curvature and tension in DEM simulations of triaxial tests of sand and ballast with two alternative flexible membrane models. Granular Matter, 26(2), Article 47. https://doi.org/10.1007/s10035-024-01419-1

In DEM simulations of triaxial tests, modelling a flexible lateral membrane is crucial and challenging. It is essential for the correct application of a uniform lateral pressure and for an accurate measurement of sample volume. Here, we introduce a m... Read More about A study of membrane correction accounting for both curvature and tension in DEM simulations of triaxial tests of sand and ballast with two alternative flexible membrane models.

Modelling the mechanical behaviour of clay using particle-scale simulations (2024)
Journal Article
de Bono, J., & McDowell, G. (2024). Modelling the mechanical behaviour of clay using particle-scale simulations. Granular Matter, 26(2), Article 29. https://doi.org/10.1007/s10035-024-01401-x

This paper demonstrates the latest developments in particle-scale modelling of a clay. It shows that by creating an initial sample of platelets featuring aggregated stacks, excellent macroscopic behaviour is achieved. This approach is justified by ex... Read More about Modelling the mechanical behaviour of clay using particle-scale simulations.

A particle-scale analysis of unload-reload hysteresis for normally consolidated kaolin (2023)
Journal Article
de Bono, J., & McDowell, G. (2023). A particle-scale analysis of unload-reload hysteresis for normally consolidated kaolin. Applied Clay Science, 246, Article 107190. https://doi.org/10.1016/j.clay.2023.107190

The mechanical behaviour of sands and clays subject to “normal” (plastic) compression are very similar, albeit at different stress levels, despite the differences in inter-particle interactions (Hertzian normal contact forces or similar for sand) and... Read More about A particle-scale analysis of unload-reload hysteresis for normally consolidated kaolin.

Relating Hydraulic Conductivity to Particle Size Using DEM (2020)
Journal Article
McDowell, G., & de Bono, J. (2021). Relating Hydraulic Conductivity to Particle Size Using DEM. International Journal of Geomechanics, 21(1), Article 0602003. https://doi.org/10.1061/%28asce%29gm.1943-5622.0001670

For over 100 years it has been accepted that the permeability or hydraulic conductivity of a soil is controlled by the size of pores through which the fluid flows, and that this pore size should be a function of particle sizes. All well-known formula... Read More about Relating Hydraulic Conductivity to Particle Size Using DEM.

Discrete element modelling of two-layered ballast in a box test (2020)
Journal Article
Li, H., & Mcdowell, G. (2020). Discrete element modelling of two-layered ballast in a box test. Granular Matter, 22, Article 76. https://doi.org/10.1007/s10035-020-01046-6

It has been recently reported that ballast comprising differently graded layers helps to reduce track settlement. The main goal of this paper is to provide micro mechanical insight about how the differently layered ballasts reduce the settlement by e... Read More about Discrete element modelling of two-layered ballast in a box test.

Micro mechanics of critical states for isotropically overconsolidated sand (2015)
Journal Article
McDowell, G. R., Yue, P., & de Bono, J. P. (2015). Micro mechanics of critical states for isotropically overconsolidated sand. Powder Technology, 283, https://doi.org/10.1016/j.powtec.2015.05.043

The discrete element method has been used to investigate the micro mechanics of shearing to a critical state on the loose and dense sides of critical. Isotropic compression has previously been modelled in 3D using a large number of particles and with... Read More about Micro mechanics of critical states for isotropically overconsolidated sand.

Investigating geogrid-reinforced ballast: Experimental pull-out tests and discrete element modelling (2014)
Journal Article
Chen, C., McDowell, G., & Thom, N. (2014). Investigating geogrid-reinforced ballast: Experimental pull-out tests and discrete element modelling. Soils and Foundations, 54(1), 1-11. https://doi.org/10.1016/j.sandf.2013.12.001

This paper presents an evaluation of the interlocking behaviour of geogrid-reinforced railway ballast. Experimental large box pull-out tests were conducted to examine the interaction between ballast and a biaxial geogrid. The discrete element method... Read More about Investigating geogrid-reinforced ballast: Experimental pull-out tests and discrete element modelling.

A study of geogrid-reinforced ballast using laboratory pull-out tests and discrete element modelling (2013)
Journal Article
Chen, C., McDowell, G. R., & Thom, N. (in press). A study of geogrid-reinforced ballast using laboratory pull-out tests and discrete element modelling. Geomechanics and Geoengineering, 8(4), https://doi.org/10.1080/17486025.2013.805253

This paper presents an evaluation of the behaviour of geogrid-reinforced railway ballast. Experimental large box pull-out tests were conducted to examine the key parameters influencing the interaction between ballast and the geogrid. The experimental... Read More about A study of geogrid-reinforced ballast using laboratory pull-out tests and discrete element modelling.

Discrete element modelling of uniaxial constant strain rate tests on asphalt mixtures (2013)
Journal Article
Cai, W., McDowell, G. R., & Airey, G. (2013). Discrete element modelling of uniaxial constant strain rate tests on asphalt mixtures. Granular Matter, 15(2), https://doi.org/10.1007/s10035-013-0396-x

Constant strain rate tests for a graded asphalt mixture under three constant strain rates have been undertaken in the laboratory. The Discrete Element Model has been used to simulate the laboratory tests with a numerical sample preparation procedure... Read More about Discrete element modelling of uniaxial constant strain rate tests on asphalt mixtures.