STUDY OF THE FRICTION SLEEPER PERFORMANCE USING 3D FEM

A special Friction Sleeper has been designed and developed in Norway in order to increase the lateral resistance in the railway track. The Friction Sleepers utilizes the high internal friction of crushed rock ballast to increase the friction between the ballast and the sleeper then to mobilize more the shear strength. Some in-situ tests have been conducted in order to validate its effects in term of lateral displacement resistance compared to classical wooden or concrete sleeper. This paper presents the FEM calculation realized to reproduce the experiments, and both 3DPlaxis Tunnel 2.0 (3DT) and 3DPlaxis Foundation 1.5 (3DF) have been used to simulate lateral movement of the railway track. The different sleepers have been modelled by considering various interface roughness ratio R, and the Hardening Soil model was used to model the ballast and the interface between sleeper and ballast. The results of the calculation have been compared to the in-situ measurements and a good agreement has been observed for both 3DT and 3DF. However, considering the differences between the two softwares, assumptions and models differ between 3DT and 3DF. This presentation will address the challenges of modelling the problem in both 3D Tunnel and 3D foundation of simulating the behaviour of a railway embankment.