Dynamic Reliability Analysis of Large-Span Structures under Crowd Bouncing Excitation

Bouncing is one of the most common human crowd activities on civil infrastructures such as sports stadiums and concert halls, where the audience tends to make their bodies jump up and down to celebrate or participate in sport and musical events. Dynamic loads are thus generated and exerted on the structures, giving unpleasant structural vibration, which may affect the functionality of the structure or even lead to a panic of the crowd. Although researchers have studied human-induced vibration from many perspectives including load models, calculation methods, criteria for serviceability evaluation, etc., there has been minimal work regarding crowd-induced reliability analysis, mainly because the stochastic feature of the crowd load as well as the mechanism describing the crowd-structure interaction is still not clear. In this paper, a framework to calculate crowd-induced structural vibration that considers the crowd-structure interaction effect is proposed and is validated through an experimental test. The dynamic parameters of the bouncing person in the crowd are adopted from a previous statistical study. The feasibility of a probability density evolution method (PDEM) is proved to be effective to calculate structural stochastic vibration under the bouncing crowd. The dynamic reliability of the structure is thus analyzed based on the stochastic responses. Results show that the consideration of the crowd-structure interaction effect significantly affects the dynamic reliability, which is also dependent on various factors including bouncing frequency, failure criteria, limit threshold, human model parameter distribution, etc. This paper provides a foundation for the performance-based vibration serviceability design of large-span structures.