The Research On Vehicle Load Effects And Truck Weight Limits Of Highway Bridges

Bridge construction brings plenty of convenience for trevel as an important part of highway engineering.The vehicle load acting on the bridge is the most important part for all the live load during the operation periods,So the vehicle load has a great influence on the safety and reliability of the bridge.In recent years,The accidents crushed the bridge caused by the overweight vehicles occur frequently.In the standard,the calculation model of the vehicle load are specified.However,the vehicle load has a strong regional and temporal variability.It was necessary to collect the measured vehicle load data for the area,In order to study the vehicle load effect of a highway bridge in a certain area.This paper based on the vehicle load data collected by the WIM system.The main research works are as follows:(1)According to the probability analysis of the measured vehicle flow was carried out for different periods and different lanes,and then the vehicle load model is established,Based on the Monte Carlo method,the vehicle load model is randomly sampled and the corresponding random flow is compiled.(2)The load effect at the critical section caused by the random traffic flow acting on the different type and different span of bridge is calculated by using the influence line loading method and compared with the load effect caused by the standard vehicle load,The probability distribution of the maximum load effect was described by the appropriate distribution type.(3)Establishing the limit state equation of the bridge structure's carrying capacity,Calculating the statistical parameters of resistance,constant load effect and live load effect,Exploring the bending resistance reliability and shearing resistance reliability at crucial section undering the random traffic flow.Research on the variation of reliability caused by the vehicle load changes and studying the change of live load effect statistical parameters under the different limited load values,According to the target reliability level of the bridge structure,a reasonable vehicle load limit level is determined.