Railway Bridge End-Approach Zone under a Moving Load: Numerical Assessment from a Geotechnical Perspective

Abstract

When subjected to moving train loads, the bridge-end transition zone becomes an important geotechnical site, requiring detailed investigation. Dealing with complex track–substructure–soil interaction is essential because of the varying stiffness at the specific region. A field data–based, validated, comprehensive numerical model can accurately evaluate the long-term performance of the end-approach zone. In this study, a comprehensive numerical approach was used to examine the transition region of an elevated railway bridge between Rohtak and Gohana in Haryana, India. To explore the overall behavior of the bridge transition zone for the investigated scenario, a static approach to replicating the moving load analysis has been successfully implemented while also considering the effects of rail pad stiffness and repetition of the load. The study revealed that using a softer rail pad significantly affects the overall behavior of the track, abutment wall, and subsurface geomaterials. With the increase in loading cycles, the zone closest to the end substructures is affected more, particularly at shallower depths, considered from the sleeper base. At the same time, because of increased stress mobilization, the deeper soil is relatively more affected when observed at a longer transition distance.