Factors to Consider in Design for Rhythmic Crowd Loading for Vibration Serviceability

Abstract

Vibration serviceability due to rhythmic loading generated by a crowd is a widely acknowledged design consideration for assembly-type structures such as stadium grandstands. However, guidance for serviceability design is rarely incorporated into a governing code. To aid designers in the process of designing for serviceability due to rhythmic crowd loading, the current state of knowledge is summarized. Topics to be presented are organized based on the various components contributing to vibration serviceability assessment: 1) excitation, 2) structural response, and 3) assessment/design. The excitation component will speak to a crowd loading to be used for design and the many factors that influence the crowd loading including the synchronization effects of a crowd, the number of harmonic components to be included, and the effects that the motion of the structure has on the crowd motion. The structural response component will focus on the estimation of the dynamic properties of a structure and how these properties are affected by human-structure interaction. The final component, assessment and design, will explain the current assessment measures for vibration serviceability including vibration dose values and RMS acceleration. The acceptable limits for these measures will be discussed as well as the various design approaches to prevent serviceability issues.