Vibration Serviceability Evaluation of Office Building Floors Due to Human Movements

The tendency of architects and engineers to reduce construction costs by using high-strength, lightweight materials, and owners’ requirements for large open spaces, along with the new trend in the use of paperless or electronic offices, have resulted in office building floors with excessive vibrations due to walking. The evaluation and assessment of floor movements are important factors that require the attention of architects and engineers. In the past, standards and design guides have simply used the time domain response of the floor when subjected to human movements and suggested limits on the peak or Root Mean Square (RMS) of acceleration for vibration evaluation. Recent standards and design guides have recommended the use of frequency-weighted response (generally acceleration) of the floor to compute the vibration dose value (VDV) in order to assess the vibration serviceability of structures. Based on the results of a number of walking tests conducted on six different office building floors over a span of 6 years, this paper proposes a relationship between VDV and the maximum transient vibration value (MTVV), which is used to recommend acceptable VDV limits to evaluate office floor vibrations. The results of this study also showed a relatively consistent relationship between the VDV and peak frequency-weighted acceleration ($a_{w,p}$). In addition, a novel usage- (or performance-) based vibration evaluation method was introduced, which is a new approach for the assessment of existing office floors and design of new office floors. In this approach, the acceptable VDV limit for one floor walk is defined based on the expected number of daily walk events. An equivalent equation in terms of the acceptable $a_{w,p}$ limit [$(a_{w,p}{)}_a$] was introduced for use at the design stage. The appropriateness of the proposed limits was verified using the subjective assessment of the tested building floors, and was compared with the provisions of the current design guides. Comments regarding the definition of high frequency floors, based on the results of the conducted studies, were made.