Discrete element modelling of geocell-reinforced track ballast under static and cyclic loading

Abstract

A geocell is a geosynthetic material developed to reinforce soils and aggregates. Similar to the configuration of a honeycomb, a geocell panel is designed to encompass consecutive confined cells where soils and aggregates are placed. The cellular confinement system of the geocell is beneficial in the reinforcement of track ballast, which helps restrain lateral movement and minimise vertical subsidence of a trackbed. To gain an understanding of the reinforcement, a numerical study has been conducted. The study uses the discrete element method to simulate the interaction between the geocell and the discrete particles of ballast. Both static and cyclic loading environments are considered. Displacements and stresses at both micro- and macro-scales are assessed for control and reinforced scenarios. The outcomes of this study seek to encourage likely reduction in trackbed thickness and width, to save construction cost and improve the sustainability of the railway trackbed.