The effect of soil improvement and auxiliary rails at railway track transition zones

Railway track transition zones are areas where there is a sudden change in the track-ground structure. They include changes between ballasted and slab track, bridge approaches, tunnel entry/exits. often location of rapid deterioration, therefore this paper investigates use auxiliary rails soil improvement to minimise train-track-ground dynamic effects. To do so, 3D finite element model developed using eight-node solid elements perfectly matched layer absorbing boundary condition. A moving train load simulated sprung mass represent train-track interaction. After presenting model, it validated against field data collected on both plain line at zone. Once validated, sensitivity study performed into improvement. It found that can improve characteristics across transition, more widely spaced provide greater benefit compared closely ones. Regarding improvement, large found, for material properties under investigation, effect stiffening than rails.