On the vibration induced by train operations in tunnels: a comparative study of different track systems through experiments and numerical simulations

The ground-borne vibration problem has been remarkably relevant in the railway field, particularly concerning annoyance in nearby buildings. This is especially true for vibrations induced by underground railways in densely populated areas. In this article, a train-track interaction model in the frequency domain is integrated with the Pipe-in-Pipe (PiP) analytical formulation. The train-track-tunnel model is employed to examine the influence of various track systems on vibrations transmitted in tunnels. A direct fastening system with hard baseplate is compared to a soft baseplate solution, a track with booted sleepers and a floating slab. The track dynamics is introduced by calibrating the model against impact tests on the track systems installed in different metro lines. These results suggest that, although the installation of floating slabs provides the highest performance in mitigating ground-borne vibrations in the frequency range 20–250 Hz, other solutions still offer significant benefits and could be considered as potentially more cost-effective alternatives for the design of low-vibration metro lines.