Multi-parameter Dynamic Traffic Flow Simulation and Vehicle Load Effect Analysis based on Probability and Random Theory

In order to evaluate the vehicle load adaptability of existing highway bridge at the operational stage, and provide a reference for the strategy of reinforcement and maintenance, a new model of multi-parameter traffic load flow simulation and vehicle load effect (VLE) analysis is proposed. In this paper, static traffic flow data was collected by weight in motion (WIM) system, and the characteristics of static traffic flow, such as gross vehicle weight (GVW), vehicle gap distance (VGD), wheelbase and the proportion of axle weight distribution (PAWD), was analyzed in different lanes. The program run by MATLAB was used to conduct the Monte-Carlo method on all kinds of traffic data collected and to generate the multi-parameter dynamic random traffic flow (DRTF) data. By loading DRTF data onto the influence line of the sample bridges (simply supported integral bridges of 20 m to 40 m), the maximum VLE under DRTF could be calculated and compared with the static VLE of Chinese current design code. The results showed that the fitting of GVW distribution should be used a skewed distribution or a kurtosis distribution. And under current daily traffic volume (DTV), the service condition of highway bridges can meet the requirement of traffic load. However, in the driveway of some heavy trucks, the VLE is greater than the value suggested in the current design code, which may cause partial damage to the bridge.