The Analysis Of Pedestrian-induced Vibration For XiDan's Overpass

In recent years,with the speeding up of urbanization,more and more people crowded into cities.In order to alleviate the pressure of the commercial street traffic,pedestrian bridges crossing the street began to appear in big business districts,which becomes a indispensable traffic tools.However,because of the uncertainty of the rush hour traffic,it also has a huge security risk behind the prosperity and development.The function of pedestrian bridges in the Commercial streets is double.Because of the geographical position,the beauty is also important except for its own function.And the characteristics of the bridge often lead to the stiffness and damping greatly reduced,at the same time natural frequency is reduced too,which can prone to vibration at the footbridge peak stage,and threat the safety of pedestrians.In this case,the most effective solution is to control the number of rows.This needs to find the right way to estimate the number of security,and provide technical advice of current limiting and security measures for the management departments.So how to accurately predict the number of bridge as much as possible becomes a great valuable topic,this paper will try to solve this problem.Through field investigation,collecting the bridge pedestrian pace,I got the average frequency through data processing.average pace was obtained through data processing,Then through the finite element software to build the finite element model of footbridge.By modal analysis,comparing with the results of modal analysis and the measured values,which ensured the practicability of the model.Based on the modal analysis results to determine the research necessity.After ensured the model accuracy,selected the mature load model and pedestrian-induced vibration research methods,according to different working condition of the crowd on the model of finite element simulation,it is concluded that the maximum acceleration under different working conditions.Finally,with combining evaluating method for evaluating the footbridge,the comfort in different working conditions is obtained,then we can get the safety number of pedestrian bridge.