Design of ballasted railway track foundations using numerical modelling Part I: Development

In this paper, a new design method for ballasted railway track foundations is developed, which can sustain high speed trains and heavy axle loads. The proposed method is intended to prevent two most common track failures, namely the progressive shear failure of track subgrade and excessive plastic deformation of track substructure (i.e. ballast + subgrade). The method is based on improved empirical models and sophisticated three dimensional (3D) finite element (FE) numerical analyses. The improved empirical models are used for predicting the cumulative plastic deformation of the track, whereas the stress parameters of the ballast and subgrade layers are obtained from the 3D FE numerical analyses. The outcomes are then synthesized into a set of design charts that formed the core of the proposed design method so that it can be readily used by railway geotechnical engineers for routine design practice. The design method can be used for various practical conditions of train-track-ground systems, including the modulus, thickness and type of ballast and subgrade. The new design method has significant advantages over existing methods and is believed to offer a major role in modern railway tack design and code of practice. The applications of the new method are presented and explained in a companion paper.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author