Static And Dynamic Analysis And Human-induced Vibration Analysis Of Space Curved Cable-stayed Pedestrian Bridge

In recent years,with the continuous acceleration of reform and opening up,China's urbanization rate has gradually increased,a large number of people from rural areas into cities.With the increase of urban population,the burden of urban traffic and pedestrian circulation has become more and more heavy,and the advantages of pedestrian overpasses have gradually emerged.With the development of science and technology,the improvement of engineering technology and the wide application of new lightweight materials,urban pedestrian bridges are developing towards long-span and soft direction,and many pedestrian bridges with peculiar and beautiful shapes have been built.However,the increase of span and the reduction of mass of pedestrian bridges will lead to the decrease of structural stiffness and structural damping,which will directly reduce the natural frequency of bridge foundation.When the walking frequency of pedestrians are close to the natural frequency of the structure,the two will resonate,which will easily lead to excessive vibration and affect the comfort of pedestrians.At present,the domestic standard only avoid excessive vibration by avoiding the lowest fundamental frequency of bridge which may produce resonance of pedestrian bridges.Therefore,this paper takes a space curved cable-stayed pedestrian bridge as an example to study pedestrian load,pedestrian bridge standard,stress state of pedestrian bridges,pedestrian-induced vibration characteristics and comfort evaluation of pedestrian bridges.The main works are as follows:(1)This paper systematically introduces the research status of pedestrian-induced vibration of pedestrian bridges at home and abroad,the characteristics of cable-stayed bridges with inclined towers,and three commonly used calculation theories of pedestrian-induced vibration.Compare and studies a variety of pedestrian bridge design specifications,focusing on the provisions of pedestrian comfort in the specifications.Summarizes the similarities and differences of comfort evaluation in these specifications.(2)Taking a space curved cable-stayed pedestrian bridge on Huandao Road in Xiamen as an engineering background and based on the large-scale finite element software ANSYS,the theoretical calculation of static and dynamic loads and the multi-condition test of the pedestrian bridge are carried out.The mechanical characteristics of the bridge are studied,which lays a foundation for the calculation of human-induced vibration.(3)The pedestrian-induced vibration response of the pedestrian bridge is calculated by Fourier series model of pedestrian load.The vertical acceleration response of the pedestrian bridge under the conditions of single person crossing the bridge with asynchronous frequency,multi-person crossing the bridge side by side and multi-person crossing in queue is studied and compared with the measured results.(4)Computing the dynamic response of pedestrian bridge under crowd load in accordance with EN03 code of Germany.Evaluating the comfort degree of pedestrian bridge according to the calculation results.Putting forward corresponding measures to limit the daily use of pedestrian flow according to the comfort degree of pedestrians under different pedestrian densities.