混合交通流理论模型构建与应用研究

AbstractAbstractIn the field of bridge design,researches are mainly on the structural system and themechanical properties,but relatively small on vehicle load and its effect.Due to the types,driving characteristics and load characteristics of the vehicles through bridge is random,thesimulation of the load effect of operating vehicles is very complex.The traffic flow theory isquite mature in the description of the vehicle characteristics and driving characteristics.Thispaper introduces traffic flow theory to better simulate and analyze the effect of bridge load byoperating vehicles.First,based on the analysis of the mixed traffic parameters,established the function ofmodel proportion and viscosity coefficient.Considering the flow rate of overtaking and lanechanging,introduced the viscous drag force composed of the resistance along the way andlocal resistance;a fluid dynamic traffic model is proposed based on fluid dynamic trafficmodel and vehicle following model.On this basis,this research solved the characteristic rootsof the new model,analyzed the overtaking rate of the balance equation,and then constructedthe difference scheme of the model.On this paper,the author analyzed the changing of trafficparameters over time and space by discrete the velocity and the density.Finally,combined themixed traffic flow dynamics model with the Monte Carlo method,then applied the MATLABprogram to establish traffic flow parameters random array and calculate the vehicle loadeffects under random traffic of typical bridges based on the measured traffic flow,speed,vehicle model ratio,wheelbase and axle load and other parameters statistics.Keywords:traffic flow;following model;overtaking