Study of the influence of geometrical and mechanical parameters on ballasted railway tracks design

Abstract

This paper investigates the vertical deflection on ballasted railway tracks from a set of cases of railway track typologies which differ in six track parameters: embankment height, ballast thickness, sleeper spacing, rail pad stiffness, Young’s modulus of the embankment material and the load applied to the structure. Finite element method has been the tool to assess the structural combinations and the results provided by linear and nonlinear analyses have been contrasted. Then, a new formulation for the deflection estimation in terms of the aforementioned parameters is presented based on a multiple regression model. The results provided by this formulation have been compared to those obtained from the classic Zimmermann theory. Finally, a stress analysis has been performed to complete the study and better understand the global behaviour of the railway structure. This article pretends to improve the design process and construction of ballasted railway tracks by means of proposing a formulation which estimates the track deflection to obtain the optimum track stiffness.