Abstract:
Transition zones to bridges and other structures are critical locations in railway tracks that frequently evidence
poor long-term performance. Under sleeper pads (USPs) are reported to reduce ballast degradation and control
the vertical stiffness of the track, which suggests that USPs can contribute to mitigating the frequent negative
effects associated with transitions zones. Aiming at understanding in greater depth the influence of USPs on the
dynamic behaviour of transition zones and at improving the design of such railway structures, the authors have
developed an extensive experimental and numerical study. 3-D FEM models using state-of-the-art numerical
approaches were successfully calibrated and validated using experimental measurements. Simulations supported
previous findings, highlighting the potential benefit of USPs and pointing to the need to careful designing of the
resilient properties of USPs and their arrangement along transition zones, so as to avoid introducing abrupt
variations in track vertical stiffness.