A structure is treated as a multi-degree-of-freedom system, and each bouncing person on the structure is treated as an individual spring-mass-damper system. The influence coefficient and mode decomposition methods are used to derive the equation of motion for the coupled system in canonical coordinates. Furthermore, the frequency response function linking the state vector of coupled system with the crowd bouncing load time history is established by the state space method. The spectral analysis solution for the equation of motion of coupled system is derived by the stochastic vibration theory, and then it is used to calculate the auto-power spectrum and root mean square value of structural acceleration response. A comparison between theoretical predictions and field-measured responses of large-span floors demonstrates that the proposed spectral analysis model and the computational method are rational, and they can be applied to analyzing and caleulating structural responses during crowd bouncing activities.

human induced vibration  /  crowd-structure interaction  /  stochastic vibration  /  bouncing load