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DEM simulation of the behaviour of geogrid stabilised ballast fouled with coal

Journal Article


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Abstract


  • Geogrids are commonly used in railway construction for reinforcement and stabilisation. When railway ballast becomes fouled due to ballast breakage, infiltration of coal fines, dust and subgrade soil pumping, the reinforcement effect of geogrids decreases significantly. This paper presents results obtained from Discrete Element Method (DEM) to study the interface behaviour of coal-fouled ballast reinforced by geogrid subjected to direct shear testing. In this study, irregularly-shaped aggregates (ballast) were modelled by clumping together 10–20 spheres in appropriate sizes and positions. The geogrid was modelled by bonding a large number of small spheres together to form the desired grid geometry and apertures. Fouled ballast with 40% Void Contaminant Index (VCI) was modelled by injecting a predetermined number of miniature spheres into the voids of fresh ballast. A series of direct shear tests for fresh and fouled ballast reinforced by the geogrid subjected to normal shear stresses varying from 15 kPa to 75 kPa were then simulated in the DEM. The numerical results showed a good agreement the laboratory data, indicating that the DEM model is able to capture the behaviour of both fresh and coal-fouled ballast reinforced by the geogrid. The advantages of the proposed DEM model in terms of capturing the correct stress–displacement and volumetric behaviour of ballast, as well as the contact forces and strains developed in the geogrids are discussed.

Publication Date


  • 2014

Citation


  • Ngo, N., Indraratna, B. & Rujikiatkamjorn, C. (2014). DEM simulation of the behaviour of geogrid stabilised ballast fouled with coal. Computers and Geotechnics, 55 224-231.

Scopus Eid


  • 2-s2.0-84885437935

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2473&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1464

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 224

End Page


  • 231

Volume


  • 55

Place Of Publication


  • United Kingdom

Abstract


  • Geogrids are commonly used in railway construction for reinforcement and stabilisation. When railway ballast becomes fouled due to ballast breakage, infiltration of coal fines, dust and subgrade soil pumping, the reinforcement effect of geogrids decreases significantly. This paper presents results obtained from Discrete Element Method (DEM) to study the interface behaviour of coal-fouled ballast reinforced by geogrid subjected to direct shear testing. In this study, irregularly-shaped aggregates (ballast) were modelled by clumping together 10–20 spheres in appropriate sizes and positions. The geogrid was modelled by bonding a large number of small spheres together to form the desired grid geometry and apertures. Fouled ballast with 40% Void Contaminant Index (VCI) was modelled by injecting a predetermined number of miniature spheres into the voids of fresh ballast. A series of direct shear tests for fresh and fouled ballast reinforced by the geogrid subjected to normal shear stresses varying from 15 kPa to 75 kPa were then simulated in the DEM. The numerical results showed a good agreement the laboratory data, indicating that the DEM model is able to capture the behaviour of both fresh and coal-fouled ballast reinforced by the geogrid. The advantages of the proposed DEM model in terms of capturing the correct stress–displacement and volumetric behaviour of ballast, as well as the contact forces and strains developed in the geogrids are discussed.

Publication Date


  • 2014

Citation


  • Ngo, N., Indraratna, B. & Rujikiatkamjorn, C. (2014). DEM simulation of the behaviour of geogrid stabilised ballast fouled with coal. Computers and Geotechnics, 55 224-231.

Scopus Eid


  • 2-s2.0-84885437935

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2473&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/1464

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 224

End Page


  • 231

Volume


  • 55

Place Of Publication


  • United Kingdom