Dynamic Simulation of T-Track: Under Moving Loads

Abstract

Though, there exists advanced ballastless track forms around the globe several thousand kilometers of 21st century railway lines are under construction with the conventional ballasted tracks. The root reasons mentioned here are huge initial investment and the need of advanced technology for ballastless tracks. Australian and South African experiences is a good example that T-Track economical alternative neither expensive as slab tracks nor problematic as traditional ballasted tracks. The spatial dynamic response of T-track (a.k.a H-Track, Tubular Modular, T-sleeper) has been analyzed by developing continuous double beam model (rail and RC beam) and continuum subgrade for dynamic analysis using a finite element modeling software - ABAQUS. The primary kinematic responses of the track are evaluated based on time and frequency domains under different modeling parameters and train speed. The effect of vehicle speed on the subgrade structure has been investigated under single and an array of moving loads and a comparison is made with ballasted track responses from literature and previous studies. Based on the T-track dynamic analysis, results are characterized by less subgrade deformation under single and multiple moving loads, higher natural frequency ranges and less vibration modes (due to being continuously supported), less vertical rail stress etc. These outputs ultimately indicate that T-track can better be applied and optimized for wide range of axle load and train speed. Specifically, T-Track can suit the climate and topography conditions of Eastern Ethiopian where Great Rift Valley and deserts are dominant.