| Serviceability limit states in buildings are conditions where the use of the building is disrupted due to excessive deformations, deterioration, or motions of the structure or its components. One major serviceability consideration in modern buildings is excessive floor vibrations. Methods for accurate prediction of these vibrations and evaluation of floor systems are not readily available to the design community.;Design aids are developed in chart form for floor systems subjected to groups walking and exercising. Each chart represents a certain type of activity and floor system, and provides a limit for tolerable peak acceleration as a function of generalized mass and stiffness for the first mode of the floor. By using one of these design charts, a designer can determine whether a specific floor system may have a potential serviceability problem.;The objective of this research is to develop methods for the evaluation of floor systems subjected to occupant activities. This development requires realistic load models, an assessment of dynamic models of the floor system, and up-to-date information on human perception and tolerance of vibrations. The occupant-induced loads are modeled as moving, random loads. Two approaches are developed. The first uses finite element analysis to calculate the dynamic response of a floor to random crowd activity in the time domain. The second approach is based on random vibration analysis in the frequency domain. The response predictions from both approaches are quite close to each other and to in-situ response measurements from prior studies. However, both methods are found to be too involved to be used in routine design. |
