Deformation behaviour of gap-graded fouled ballast evaluated by a 3D discrete element method

作者：Kumara Janaka J^*; Hayano Kimitoshi; Kikuchi Yoshiaki

来源：KSCE Journal of Civil Engineering, 2016, 20(6): 2345-2354.

DOI：10.1007/s12205-015-0377-1

• discrete element method
• fouled ballast
• fouling index
• packing behaviour
• stress-strain behaviour
• triaxial compression test

The ballast fouling has been identified as a challenging issue in ballasted railway tracks due to huge maintenance costs. In this research, the deformation characteristics of gap-graded fouled ballast were studied from laboratory experiments and a Discrete Element Method (DEM). The fouled ballasts were prepared with different values of a fouling index, FI (p). After the packing behaviour of fouled ballasts was studied by density tests, the stress-strain behaviour of them was studied from triaxial compression tests under both dense and loose states. It was found that the void ratio decreases with FI (p) up to 50%, then it increases with FI (p). The results also indicate that the strain-hardening behaviour of ballast is weakened when fouled by FI (p) aeyen 30%. The DEM simulation by clump particles produce a similar stress-strain behaviour as the laboratory specimens than their spherical counterparts. The results also reveal that the dilation behaviour of ballast is deteriorated significantly when fouled by FI (p) > 50%. The peak frictional angle indicates that the strength properties of ballast are deteriorated significantly when fouled by FI (p) aeyen 30%. Therefore, we recommend that fouled ballast should be treated by a maintenance application when ballast is fouled by FI (p) > 30%.

• 出版日期2016-9