An Experimental Methodology for the Assessment of Ground-Borne Vibrations due to Railway Vehicles

This paper shows the procedure and setup used for assessing the impact of a railway vehicle on the infrastructure in terms of ground-borne vibration. The proposed methodology relies on the definition of the so-called Force Density Level (FDL) proposed by the US Federal Transit Administration (FTA). To compute the FDL, vibration levels at different locations should be measured. The contribution associated with the dynamic behaviour of the ground should be removed, and this has been done by proposing impact tests carried out using a dedicated machine designed for this purpose. Results show that the FDL is almost independent of the measured line used for the computation up to 80 Hz, while some differences occur at higher frequencies. Additionally, for the considered vehicle (a modern articulated tramcar), the dependence on speed is investigated, showing no clear trend.