Study On The Accumulated Axle Load Of Expressway Pavement Based On The Data Of Network Tolling System

With the rapid increase of car ownership in our country,the expressway network expands rapidly.Networked tolling system can not only provide convenience for travelers,but also stores huge amounts of traffic data.In this paper,the traffic volume of each section was estimated based on the highway network toll data and traffic assignment model.Then,according to the distribution results,the accumulated axle load of the pavement was studied,which provided theoretical basis for road design and management of road maintenance.First of all,this paper collected the network tolling data and the unreasonable data was processed for controlling the data quality,and then an OD missing data model was established to obtain the OD matrix depending on the relationship between the travel distance and the travel proportion.Secondly,several common traffic assignment methods were briefly introduced and the Logit multi path non-equilibrium assignment algorithm was chosen according to its own characteristics.The selection of road resistance function caused by different vehicle types was studied and the BPR function was chosen as the resistance function of the small vehicle.Generalized road resistance function considering the time value,fuel cost and toll date was established for the oversize vehicle.Subsequently,the road resistance function and distribution model were calibrated and the traffic distribution model of different models was constructed.Again,based on MATLAB data processing software platform,the new traffic assignment model was verified between a total of 155 nodes based on the OD data from the South Road Expressway in Hebei Province,and based on the measured data accuracy test to the model,it was showed that the distribution of the model results were highly close to the real situation.Finally,the cumulative load action times of the section were calculated based on the obtained traffic assignment data,and the concept of "Axial Age" was put forward.By comparing with the natural age,it was found that the great difference existed and the axial age could reflect the degree of damage and the demand for maintenance more realistically and objectively.