Research On Vertical Vibration Analysis And Vibration Reduction Control Of Pedestrian Bridge Under Crowd Load And Earthquake

In recent years,as materials and bold innovation in structure grows,pedestrian bridge at home and abroad now have the advantages of large span,light weight,and pretty outline.Compared to structures with large mass and stiffness,such structures are prone to generate large structural vibrations under dynamic loads,which can cause discomfort to pedestrians and even panic among the population,and even lead to structural damage and destruction.In this paper,the pedestrian bridge is taken as the research object,and a systematic study is carried out for the dynamic response and vibration control of structures under the crowd load and the earthquake action,mainly from the following aspects: structural response rules under the crowd load,the earthquake action,and the earthquake crowd combined action,the structural vibration comfort evaluation,and the structural vibration reduction design.The main contents include:1.Based on the social force model which was proposed in the field of pedestrian transportation,combined with relevant pedestrian dynamic parameters,a MATLAB simulation program was developed to simulate pedestrian motion on a pedestrian bridge,obtain the motion parameters of pedestrians at any time.Combined with the walking load model in the form of Fourier series,a random crowd load model was built,which considers the uncertainty between individuals,other pedestrians and the environment.2.Based on the stiffness fiber beam element,a MATLAB numerical analysis model of the pedestrian bridge structure was established,and a SAP2000 finite element model was constructed to verify it.Based on the numerical analysis model of pedestrian bridge,the structural vertical vibration response rules of structures under the action of the crowd load and the earthquake alone and under the combined action of the earthquake and the crowd were analyzed,and the influence of earthquake action on the structural vertical vibration response caused by the combined action of earthquake and crowd was discussed.3.The relevant specifications for the vibration comfort of pedestrian bridges at home and abroad were systematically introduced,summarized and compared.A new evaluation method and index limit value for the vibration comfort were proposed from the perspective of the annoyance rate.4.Based on the optimization design formula,TMD,TMDI,and PTMD vibration reduction systems for pedestrian bridge under the combined action of earthquake and crowd loads were designed,and the vibration reduction effects of different vibration reduction systems were compared and analyzed.