Walking Parameters And Aerodynamic Parameters Of Wind-Pedestrian-Bridge System

The dynamic loads acting on long-span pedestrian suspension bridges are mainly pedestrian loads and wind loads.When pedestrians,wind loads and bridges coexist,the interaction between the three constitutes a coordinated vibration system.The vibration response of the bridge under the single load affected by the coupled vibration may be amplified,resulting in uncomfortable pedestrian walking and affecting the performance of the bridge.Accurate calculation of wind-pedestrian-bridge interaction requires a comprehensive consideration of the interaction between pedestrians and bridges,the fluid-structure interaction of wind and bridge,and the characteristics of the system over time.Based on this,this paper expounds the development status and characteristics of pedestrian suspension bridges,and briefly reviews the research status of bridge buffeting,pedestrian-induced vibration and wind-pedestrian-bridge cooperative vibration.This article has done the following work:Firstly,this paper briefly reviews the human-induced vibration theory,and determines the basic parameters of human-induced vibration calculation,such as step frequency and stride,according to the dual characteristics of walking load time and space.However,pedestrian walking parameters are affected by pedestrian walking status,gender,race,and surrounding environment and the study of pedestrian walking parameters in China is still blank.Therefore,this paper takes the Jiufengshan pedestrian suspension bridge in Yanping District of Nanping City as the observation site,and uses the combination of video recording and manual screening to observe the pedestrians walking on the Jiufengshan suspension bridge.The pedestrian frequency,stride and speed parameters corresponding to different genders and ages were obtained by manual screening,and the distribution characteristics of pedestrian walking parameters were studied in detail by statistical methods,further based on the stride frequency,stride length and walking speed.The relationship between the three establishes a relationship between the three.Secondly,when calculating the wind-induced buffeting of the bridge,it is necessary to consider the effects of static wind load,buffeting force and flutter self-excitation.The presence of pedestrians will interfere with the flow field around the bridge section,thus changing the three-component force coefficient and the flutter derivative of the section,which in turn affects the chattering calculation results.Therefore,this paper designs the force test and vibration test of the human-bridge segment model with different densities and different arrangements.According to the test results,the variation of aerostatic coefficients and flutter derivatives of the human-bridge system with the pedestrian density is analyzed,and the influence of the pedestrian arrangement on flutter derivatives is analyzed.According to the relationship between aerostatic coefficients and the buffeting force,the influence of the pedestrian density change on the buffeting force is qualitatively analyzed.Finally,according to the typical section flutter driving mechanism,the effects of different density and arrangement on self-excited vibration are analyzed.