Surface Train and Subway-induced Ground Vibration Characteristics for Full-Scale Buildings

Surface train and subway-induced vibrations have been a concern in buildings located in the vicinity of railway lines. Operation of sensitive equipment in laboratories and precision manufacturing facilities can be affected by undesired levels of building vibration. New residential building developments in proximity to railway lines have been in question for human comfort. Cost effective mitigation techniques require a good understanding of the nature of these railway-induced base excitations of buildings. In order to understand the characteristics of surface train and subway-induced building floor vibrations, exploratory site vibration measurements were performed at seven full-scale buildings in the Boston area. Tri-axial vibration measurements were made on grade slab of buildings and in adjacent open fields at the same distance from the tracks. Vibration measurements were also made at an internal column location at the foundation level of one building. These vibration measurements were quantified and compared. It is found that in case of train-induced building vibrations, open field data can be used in design of buildings. However due to inconsistency in observations, similar conclusion is not drawn in case of subway-induced building vibration. Findings from these observations in the open field and constructed facilities responses should accordingly be considered in design phase of buildings.