An experimental study of embankment conditions on high-speed railway ground vibrations

High-speed rail infrastructure has been developed considerably in Europe, creating a dense rail network that links major capital cities. Although it has been the subject of continuous technological innovation (comfortable trains, ERTMS, embankment adaptation, ⋯), high-speed rail causes elevated ground vibration levels, due to the large weight and speed of the moving load. This paper presents recent vibration measurements collected at Belgian sites during the passing of Thalys, Eurostar and French TGV Réseau high-speed trains. In common with other engineering disciplines, railway ground vibrations are increasingly studied using computer simulation. Despite this, experimental measurements are important for both investigating ground vibration phenomenon and for the validation of numerical models. The proposed study is in line with the development of high speed rail line in the United Kingdom, by focusing on the parameters and configurations that influence ground surface motion. A detailed analysis of the selected sites is performed in terms of soil dynamic parameters by using the MASW method. Three track configurations are investigated by comparing the effect of possible embankment (backfill or excavated) on the ground vibration level with respect to the distance from the source. It is found that the embankment case causes lower peak particle velocities than the cutting and at-grade cases which present comparable vibration levels. Particular attention is paid to the impact of the train and the soil configuration, as well as the direction of measurement, in both the near and far field.