Numerical validation of the generalized equivalent spectral model through crowd dynamics simulations

This paper aims to provide a validation of the Generalized Equivalent Spectral Model of pedestrian-induced loading through numerical simulations of crowd dynamics. Pedestrian flows with varying density are numerically simulated based on the social force model. The instantaneous step frequency of each pedestrian is obtained from his instantaneous velocity. Results obtained from numerical simulations are statistically analyzed to obtain probability density functions of the step frequency. Then, each pedestrian is modelled as a moving harmonic load, whose trajectory and velocity are obtained from crowd simulations. The power spectral density function of the modal force obtained from numerical simulations is then compared with the analytical expression provided by the Generalized Equivalent Spectral Model. Possible modifications of the original formulation are analyzed, in order to fit numerical results.