Ground-borne noise and vibration: classification of railway vehicles based on a track-independent vehicle indicator

Abstract

Abstract Within the SILVARSTAR project, a track-independent vehicle indicator (TVI) is proposed that can be used to identify railway vehicles which generate low ground-borne vibration and noise levels. The proposed TVI is based on applying a frequency weighting to the force density, which may be obtained at a site from the measured ground vibration velocity levels due to train passages and the measured line source transfer mobility. Two different formulations of TVI are proposed; one related to ground-borne vibration and the other to ground-borne noise. Each TVI is a single number quantity, defined as a sum over all frequency bands of the frequency-weighted force density levels. The proposed performance classification of different vehicles can be achieved by comparing the relative differences of their TVIs. A series of test cases is used to demonstrate the calculation of the TVIs and the TVI-based classification of different vehicles at the same site. Although the values of the TVIs for each vehicle may vary due to the different modelling approaches and detail, or due to the limited knowledge of the input parameters used for the target site, the TVI-based classification of different vehicles is found to be insensitive to this model and parameter uncertainty.