Pedestrian Comfort Analysis Of Double Deck Steel Truss Bridge Based On Vehicle Bridge Coupled Vibration

With the development of economy and society and the increase of urban population,the demand of traffic flow is increasing day by day.The construction of the bridge shared by people and vehicles has become a way to solve the problem of urban traffic congestion.The double-layer steel truss bridge has the characteristics of upper traffic capacity,strong crossing capacity and easy to build,which has become a common type of bridge used by people and vehicles.With the increase of traffic flow and people flow,the impact of vehicle bridge coupling vibration on pedestrian comfort is becoming increasingly prominent.At present,there are more researches on the vehicle bridge coupling vibration analysis of highway bridges,but less researches considering the influence of vehicle bridge coupling vibration on human comfort.Therefore,based on the theory of vehicle bridge coupled vibration analysis of highway bridges,according to the relevant standards and indicators of human comfort evaluation,this paper forms a human comfort evaluation method based on vehicle bridge coupled vibration response,establishes a bridge human body analysis model,analyzes the influence of different parameters on human comfort under vehicle bridge coupled vibration,and carries out human comfort under the effect of random vehicle flow evaluation.The main research contents are as follows:(1)Based on the theory of vehicle bridge coupling vibration analysis of highway bridge,the bridge and vehicle are divided into two independent subsystems to establish its motion equation.The direct integration method is used to solve the vibration balance equation of vehicle bridge.The displacement coordination and mutual force balance conditions at the contact point of vehicle bridge are satisfied by iterative operation,and the dynamic response of vehicle bridge is obtained.According to the relevant standards and indicators of human comfort evaluation,two evaluation methods of comfort and annoyance rate are formed from the root mean square value of human acceleration.The third evaluation method obtains the human physiological response frequency through the spectrum analysis of human acceleration,and evaluates human comfort according to the frequency range.(2)Select the human body analysis model and comfort evaluation model,use the ANSYS software to establish the finite element beam lattice model of the double deck steel truss bridge,attach the human body analysis model to the bridge finite element model to form the bridge human body dynamic analysis model,and transform the data of the bridge human body finite element model according to the data format of the existing vehicle bridge coupling vibration analysis program.(3)Using the existing analysis program of vehicle bridge coupling vibration of highway bridges,the dynamic response of human body under the action of different speed,vehicle weight,vehicle axle weight ratio,driving distance and random traffic flow is calculated.Combined with the human body comfort evaluation model,three methods are used to evaluate human body comfort,and the influence law of vehicle bridge coupling vibration on human body comfort under different working conditions is discussed.