Jul 03

Evaluating the performance of different sleeper shapes and materials

Toshan Rampat, Dr Louis Le Pen, Prof William Powrie, Dr John Harkness and Dr Antonios Zervos

Railway Engineering-2019

15th International Conference & Exhibition

3rd -4th July 2019


Sleepers are conventionally designed in a cuboid shape of similar volume regardless of the material of construction. However, the bending stiffness and load transfer into the track bed is material dependent; and modifying the shape of sleepers by making use of advances in manufacturing ability could improve load transfer characteristics. A parametric study was performed on 6 different shapes of concrete and composite sleepers resting on 4 different types of support to understand which shape works best with each the different support condition. The sleeper shapes and support conditions were modelled using two methods (1) a 2D beam on elastic foundation formulation solved by the finite difference numerical method and (2) a 3D finite element method. Comparison of the results demonstrated that the 2D FDM method was able to reliably predict important characteristics of behaviour – the deflection, pressure and bending moment profiles. The FDM was then used to compare the performance of the different sleeper shapes. The sleeper performance was evaluated for least differential deflection and pressure considering the volume of material used and the lowest range of bending moments present. The overall differential deflection was greater for the composite sleepers than for concrete, but greater improvements were observed for the optimised composite sleeper shapes. The difference between the negative and positive bending moments reduced as the height of the middle section of the sleeper increased and the support in the middle part increases. On average, sleeper with a larger bending stiffness in the middle performed better.