ABSTRACT
This paper presents a prediction method for floor vibrations from aerobics illustrating a case of two similar buildings one of which had a vibration problem at the lounge adjoining to an aerobics studio. The cause of the problem was quasi-resonance of the first mode of the floor and the second harmonics of the aerobics excitation. A countermeasure based on simulation results settled the problem. A study of how force is employed to the floor demonstrates that the floor vibration from aerobics with dozens of participants can be predicted accurately by the response to the force of around eight people in phase and multiplying it by the root of the number of participants divided by the number of people in phase.
