Numerical analysis on combinations of geosynthetically reinforced earth foundations for high-speed rail transportation

Abstract

High-speed trains, including freight transport, require a high-quality railway track resting on an excellent foundation to handle large deformations and vibrations. The tracks are generally laid on either cuts or fills. A geosynthetic reinforced embankment with or without a retaining wall is mainly used for fill sections. The present study attempts a moving load analysis on a ballasted rail track resting over different geometries of the geosynthetically reinforced embankment. Elastoplastic material models with material damping and infinite boundaries were applied to the model used in the analyses. A pressure-loaded areal patch was moved at a constant speed causing the load motion at semi-high and high-speed. The effect of reinforcing agents on fill section configurations, including their approximate construction cost, was analyzed. Dynamic responses of the moving load are analyzed along the lateral and the vertical direction from the application of the load. The study shows that the ground acceleration decreases by 50 % with geosynthetics and facing walls in the speed range of 100 to 400 km/h. It was also inferred that the bulk mass of earthen embankments is not enough to counter large vibrations.