Study On Coupling Vibration Of Windmill Bridge For T-beam Continuous Rigid Frame Bridge In High Altitude Area

Under the action of wind load,the safety and comfort of vehicles running on vibration bridges and the determination of the critical wind speed standard for closed traffic under strong wind have attracted more and more attention.At present,the determination and decision-making of speed limits of vehicles on bridges and related indicators of closing bridges under strong wind are lack of quantitative data support.Because of the characteristics of high-altitude Canyon area,such as high wind,high wind speed and extremely uneven surface,the piers are generally built higher,which poses a certain threat to the stability of high piers.In addition,the irregular vibration of high-pier bridges in the wind field has brought remarkable safety of vehicles on the bridge and comfort of passengers.Therefore,the study of wind-vehicle-bridge spatial coupling vibration of high pier bridges in high-altitude canyon area is of great significance for practical engineering construction.Specific research contents are divided into the following aspects:1.The interaction among subsystems in the wind-vehicle-bridge system is discussed in detail;the wind loads acting on the bridge are analyzed.The wind loads are divided into static wind loads and fluctuating wind loads,which are applied to the bridge and vehicle models respectively to calculate their effects on the vibration response of high pier bridges;the structural geometry of high pier bridges is considered.A reasonable analysis method is established to estimate the vibration response of bridges under strong wind and vehicle moving loads.The effects of structural type,geometric nonlinearity,vehicle speed,wind speed and wind action form on the maximum vibration response of bridges are analyzed.2.Considering that the coupling vibration of windmill-bridge directly affects two aspects of the system quality:(1)the impact of fast-moving vehicles and changeable wind on the passing bridges directly affects their working status and service life;(2)the vibration of bridges has an impact on the stability and safety of the running vehicles,making them become Important considerations for evaluating the rationality of structural dynamic design parameters.Therefore,the dynamic action of windmill-bridge coupling system is comprehensively studied,the dynamic performance of the bridge and the vehicle travelability are scientifically analyzed and evaluated,the reliability of the bridge under various operating conditions is reasonably judged,and the critical wind speed of vehicle safe driving is put forward.3.This study focuses on the safety of vehicles running on T-beam continuous rigid frame bridge.CFD software Fluent is used to simulate different types of vehicles(large container vehicles,travel buses,vans,cars)to obtain the aerodynamic parameters of the vehicle-bridge combination system.Based on the theory of vehicle dynamics,the dynamic analysis models of different types of vehicles are established.The dynamic response of vehicles and the driving safety of vehicles are studied by using the method of wind-vehicle-bridge coupling vibration analysis.