THE MODAL PARAMETER IDENTIFICATION AND CROWD-INDUCED VIBRATION ANALYSIS OF FLOOR OF LARGE-SPAN WAITING HALL

摘要

In order to build suitable crowd-induced load models that are more applicable on large-span floor of waiting hall and study the crowd-induced vibration features of the large-span waiting hall,Beijing South Railway Station,which is in the spring festival peak travel season,is taken as the study object.Vibration test on the floor of the large-span waiting hall is firstly conducted.After the time-domain filtering for the data,STD,PRCE and SSI are utilized respectively to identify the natural frequency and damping of the structure.Moreover,a modified finite element model of the floor of the large-span waiting hall is established to analyze the structural modal characteristic.The effectiveness of the three modal identification methods to large-span floor will be evaluated and the dynamic properties of this structure will be analysed.Then on the basis of the conclusion of accurate crowd-induced load model,the hypothesis setting upon ideal mathematical model and the common equivalent crowd-induced load model,the paper simplifies the stochastic crowd load model,which considers the probability distribution of human gait parameters.And on the basis of the research result in transportation and biological fields by Venuti and Bruno,the predictive crowd load model,which reflects the relationship between the pedestrian flow density and the pedestrian velocity is generated.Finally,through comparing and analyzing the vibration responses of the floor of large-span waiting hall under different load models,the merits and demerits and the application scopes of each method are discussed.These conclusions will provide theoretical foundation for the development of accurate crowd-induced load model that is more workable on large-span floor.