Mechanistic Modeling of Conventional Rail Tracks to Predict the Total Permanent Deformation

A traditional ballasted railway track, characterized by its layers of ballast, sub-ballast, and subgrade, is the most viable option for Indonesia's railway system, primarily due to its cost-effectiveness and straightforward construction process. This track type must ensure a stable train route, maintaining appropriate horizontal and vertical alignment. Each component of the system is required to fulfill its designated role effectively. However, prior research has predominantly concentrated on assessing the permanent deformation of individual layers within conventional rail tracks. It has been determined that employing a linear elastic material model is inadequate for accurately representing the behavior of ballast, sub-ballast, and subgrade. The prevailing approach in existing literature involves simulating the inelastic behavior and modeling the permanent deformation of granular and soil materials in railway tracks using elastoplastic constitutive models, such as the Mohr-Coulomb and Drucker-Prager (Elastic Perfect-Plastic) models. In this context, the present study aims to evaluate the efficacy of mechanistic modeling in predicting the overall permanent deformation of conventional rail tracks, utilizing the Modified Drucker-Prager Cap model for the ballast, sub-ballast, and subgrade layers. Additionally, this research examines the contributions of each component layer to the total permanent deformation in the design of conventional rail tracks. A key finding from this investigation is that the ballast layer plays a crucial role in the permanent deformation of the conventional track, followed by the subgrade and sub-ballast layers.