Computational Modelling Group

Reinforcement of Ballasted tracks

Started
21st October 2015
Ended
18th October 2016
Research Team
Toshan Rampat

DEM Simulation

Ballast was modelled by agglomerating spheres to mimic the behaviour of breakage. The geocell was a clump of small spheres, while bitumen was modelled as visco-elastic spheres and settlement was observed for each reinforcement scheme. Experimental tests were also performed on a single geocell to check the damping ratio and the increase in bearing capacity. A small cyclic compressive test using a tensile machine was performed to check the optimum geometry of geocells and the increase in lateral confinement. A large box test was also performed in order to validate DEM results and to check the benefits of implementing the reinforcement. It was concluded that bitumen decreased vibration by prevent settlement but did not contribute in reducing the lateral vibration or lateral load. Geocell served to enhance the properties of ballast by deducing the lateral force but settlement was much significant since interlocking between ballast was reduced. While geocell amplified the settlement and movement of ballast, bitumen decreased the its damping properties of ballast.