Frequency-Dependent Analytical Model for Ballasted Rail-Track Systems Subjected to Moving Load

Abstract

A new frequency-dependent analytical model of railway substructure stiffness is proposed for analyzing ballasted rail-track systems subjected to motion-induced dynamic loading. The proposed model incorporates the effects of all essential substructural components, such as sleepers, rail pads, ballast and subballast, and subgrade. It was found that incorporation of sleepers may induce large deflections in the rail-track system at the isolation frequency of the sleeper-substructure system. Furthermore, consideration of the flexibility of the sleeper beam (incorporated by using frequency-dependent stiffness of the substructure) may significantly influence the response of the railway-track system. It was also observed that the incorporation of damping into the system reduced the rail-beam deflections without altering the critical velocity. The reliability of the proposed model was assessed through comparison with an experimental study. Contrary to the case of contemporary models, the computational time for the dynamic analysis in this case was much smaller, thus making the proposed model well suited for engineering practice.