TY - JOUR AU - Ngoc Trung Ngo, AU - Cholachat Rujikiatkamjorn, AU - Buddhima Indraratna, PY - 2016/11/30 Y2 - 2024/03/29 TI - DEM MODELLING OF GEOCELL-STABILISED SUB-BALLAST UNDER CYCLIC LOADING JF - GEOMATE Journal JA - INTERNATIONAL JOURNAL OF GEOMATE VL - 12 IS - 31 SE - Articles DO - UR - https://geomatejournal.com/geomate/article/view/1061 SP - 23-29 AB - <p>Upon repeated train loading, sub-ballast aggregates, placed underneath a ballast layer in rail<br>track, become degraded and fouled by the progressive accumulation of external fine particles such as mudpumping of soft subgrade, seriously decreasing the shear strength and drainage capacity of the track. This<br>paper presents a study of the load-deformation response of geocell-reinforced sub-ballast under cyclic loads<br>using laboratory tests and discrete element method (DEM). A series of large-scale cubical triaxial tests with<br>and without geocell inclusions are conducted in the laboratory and simulated in DEM to investigate the<br>beneficial effect of the geocells in decreasing the lateral and vertical deformations of railway subballast.<br>Irregularly-shaped particles of sub-ballast are modelled by connecting and bonding of many circular balls<br>together at appropriate sizes and positions. The geogcell was simulated by bonding many small spheres<br>together to build a desired geometry and structure. The load-deformation behaviour of the geocell-stabilised<br>sub-ballast specimen at varied load cycles predicted from the DEM modelling agrees well with those<br>measured experimentally, showing that the proposed DEM model in this study is able to capture the<br>deformation behaviour of the sub-ballast stabilised by the geocell. Additionally, the DEM modelling also<br>provides insight into the distribution of contact forces, average contact normal and shear forces, which cannot<br>be determined experimentally. These observations clearly prove the reinforcement effect of the geocell in<br>eliminating the deformation of sub-ballast from a micromechanical perspective.<br><br></p> ER -