Railway ground vibrations: Influence of train geometry and masses

This paper uses a sensitivity analysis to quantify the dominant train properties that contribute to ground-borne vibration generation, with the aim of reducing the complexity of train-track numerical models. This research is significant because groundborne vibration from railways is a growing problem, particularly in urban areas. Despite this, attempting to predict vibration levels is complex because there are many variables that contribute to the overall dynamic response. Therefore a deterministic approach is commonly used, that ignores many of these variables. Thus this paper identifies the variables that can be ignored, while highlighting those that are highly influential on vibration generation. To do so, a previously validated two and a half dimensional finite element-boundary element approach is used to simulate dynamic train-track interaction. It is computed many times for a variety of modelling variables to investigate the effect of each on the ground-borne vibration levels in the far field. It is found that increases in unsprung mass of the train cause a large increase in vibration levels.