Mitigation measures for open lines against vibration and ground-borne noise: A swiss overview

Abstract

A new Swiss ordinance, planned to come into force in autumn 2008, will demand mitigation measures for groundborne vibration over the whole existing Swiss railway network. Swiss Federal Railways (SBB) tested several mitigation measures on open lines and in tunnels. Under ballastmats: For open lines the tracks with under ballast mats need enhanced lateral support of the ballast to stabilize the ballast. The under ballast mats on open lines show some reduced insulation efficiency especially for dam situations in contrast to tunnels. Under sleeper pads: First results in Switzerland show that insulation efficiency of under sleeper pads is very similar for open lines and tunnels and comparable to under ballast mats on open lines. Mitigation measures for switches: Measurements of SBB demonstrate that so far a movable frog for switches is not a satisfying solution for vibration control. Two recent Swiss studies adjacent to a switch illustrate that the insulation efficiency of trenches is effective with about 6 dB over a large frequency domain (20/25 Hz to 250 Hz). Finally SBB proposes a simple cost-benefit-method for vibration and ground-borne noise similar to a method used in Swiss noise abatement. © 2008 Springer-Verlag Berlin Heidelberg.