Floor Vibrations of Steel-Framed Floor Systems Due to Rhythmic Activities-Case Study

Human induced vibrations on steel-framed floor systems can result in a wide variety of serviceability problems, ranging from discomfort of building occupants to damage of building components. Rhythmic activities, like aerobics, have the potential to cause significant floor vibrations owing to synchronized crowd movement. This article presents the results of a case study in which the susceptibility of a steel-framed floor system to structural vibrations was evaluated after an aerobic dance event caused damage to non-structural building components. The study assessed a floor supported by a system of long span trusses, which at one end were themselves supported by a two-story deep long span truss. This study consisted of collecting onsite vibration measurements and evaluating the floor system using a numerical model. The finite element analysis model was calibrated using results from field measured data. The numerical analysis results showed that estimated floor accelerations exceeded standard limits for different types of rhythmic activities, indicating that the floor system was susceptible to uncomfortable vibrations. Possible methods to improve the structural response of the floor and to address human discomfort are discussed.