Vertical Displacement Distributions of Double-Track High-Speed Railways' Ballastless Track Infrastructure

Abstract

This paper centers on the slab ballastless track widely used in China high-speed railway, using ABAQUS finite element software, establishes double-track high-speed railway vehicles-track-roadbed system secondary vertical coupling dynamic finite element model, and systematically analyzes the temporal-spatial distribution of subgrade bed vertical displacement in the situation that China Railways High-speed 3(CRH3) trains run in opposite directions. The result shows that when the distance of two trains running in opposite directions is more than 35 m, vertical displacement in the middle section of bedding is zero, which means that train load has no effect on the bed in the middle of longitudinal spacing. When the distance decreases from –20 m to –120 m, the vertical displacement decreases in oscillation type and gradually tends to zero finally. The vertical displacement peaks at the center of a single line. There exists an inflection point where vertical displacement significantly decreases at 4.11 m away from centerline of double-track subgrade. Bedding bottom vertical displacement transverse distributions along the route tend to be more even and basin-shape. Within the scope of 7.2 m from the bedding surface, the increase of vertical displacement along the depth basically decays linearly. In the range of 7.2 m to deeper, the attenuation of vertical displacement is relatively slow.