| Floor vibrations arising from normal human activity may affect the serviceability of modern building structures, which are becoming lighter and more flexible. In this dissertation, a detailed literature review regarding building floor vibrations was performed. This contained a review of human perception to vibration, typical forcing functions induced by human activities, inherent damping of floor systems, and existing criteria to control floor vibrations. Five simple dynamic models the were created to test the accuracy of the SAP90 finite element program for performing time history analyses. The close agreement between SAP90 finite element results and theoretical results indicates that the SAP90 can be used as a reliable research tool to predict the response of linear dynamic systems. Two realistic loading functions obtained from a person continuously walking and from the heel drop test were used in the SAP90 analysis to evaluate the floor serviceability due to vibrations. Thirty-six steel beam-girder floor models and the steel joist-girder floor model for office/residential buildings designed statically were evaluated by four existing vibration approaches and by the SAP90. It was found that the fundamental natural frequency obtained from the Allen and Murray approach and the Murray approach are very close to that obtained from the SAP90 analysis. For non-composite steel beam-girder floor systems, the Murray and Modified Reiher-Meister approach is recommended for use in residential buildings and the Murray approach is recommended for use in office buildings without full partitions. Office/residential buildings are unlikely to experience objectionable vibrations if full partitions are provided or if the thickness of the concrete slab is not less than 3.5 inches. Based on the SAP90 analysis, resonance is not expected to control and floor vibration can be treated as transient vibration. Thus, damping is the most important factor for office/residential buildings. Increasing the slab thickness is a very effective way to reduce vibration problems. It was also found that the transverse effect between the beams due to the continuity of the concrete floor may be neglected for steel beam-girder floor systems, but it may have an effect on steel joist-girder floor systems where vibration problems are more likely to occur. |
