Simulation Of Crowd Load And Vibration Response Analysis For Large-Span Floor Structure

With the increasing of large-span floor structure, engineering case which exceed the limit requirements of human comfort have occurred frequently, this kind of structure has attracted more and more attention. But the research of vibration response for this kind of large-span floor structure is less and the engineering design practice is lack of theoretical guidance, especially for the research of vibration response calculation and control excited by crowd, mainly displays on the uncertainty of foot while people walking, thus establishing reasonable model of crowd load has important theoretical and practical significance for rational design and normal use of large-span floor structure. The paper taking the group of large-span floor structure of high-speed rail station as the main research object, The main research work and achievements are as follows:1. The statistical analysis of the characteristic parameters for crowd walking. The paper statisticed and analyzed the characteristic parameters of crowd walking in Nanjing south railway station, Shanghai hongqiao railway station, Beijing south railway station, Wuhan railway station and Guangzhou south railway station by using the MATLAB video analysis program, obtained the distribution rule of characteristic parameters for these five high-speed rail station; it is concluded that on the whole the stride frequency obey normal distribution as μ=1.8811, σ=0.1766, the crowd walking phase obey uniform distribution as a=0, b=2π while the crowd are walking free; At the same time, the factors of affecting crowd walking were summaried, the probability of synchronization for crowd walking in the entrance hall obey normal distribution as μ=0.2516, σ=0.0672 and obey normal distribution as μ=0.1880, σ=0.0571 in the waiting hall by using the method of probability distribution; According the statistical parameters between different crowd density, the relationship between the crowd walking characteristic parameters and crowd density is fitted finally.2. The simulation of random crowd walking load. Based on the statistical of characteristic parameters of walking, and reference the single walking load model that IABSE suggested, the paper compiled a program that generate the time history curve of random crowd walking load by using MATLAB.3. Analysed and calculated the vibration response induced by crowd of the large-span cantilever in MinHang museum, obtained the vibration response induced by human as using deterministic load, random load and synchronous probability, and compared the calculation result for this three methods, which proved that the simulation method of the random crowd load is reasonable and the crowd walking synchronization probability which the paper statistic is accurate.4. The field test and calculation analysis of long-span floor structure is carried on. Using large-span cantilever of MinMang district ecological museum as the engineering background, the dynamic characteristics test is carried on, so as the vibration response incented by crowd walking before and after the vibration control; Using the same load of the field test to calculate the vibration response induced by crowd, the calculation result and the field result is generally fitted, which laid a foundation for subsequent analysis.5. The vibration response control of large-span floor structure. The field test and theoretical calculation show that the peak acceleration response of the large-span cantilever in MinMang district ecological museum incented by crowd walking is exceed the standard limits and should have the vibration control, through the optimization calculation the paper determine using six sets of TMD-fluid viscous damper energy dissipation system in order to control the vertical vibration of the structure, the theoretical calculation and the field test show that the effect of vibration response control is very obvious.