Research on the design method of the automobile design load of the small span bridge in the heavy traffic volume

Based on the vehicle load survey data measured by High speed dynamic weighing equipment in Luogang Section of National Highway No. 107 and the basic theory of probability and statistics, the parameters such as gross vehicle weight, axle load, wheelbase, vehicle spacing and so on, are statistically analysed in this paper so as to confirm the probability distribution function of the category vehicle load and the representative values of related parameters. The simulation program of random fleet across the bridge was compiled by MATLAB. According to the calculation analysis of the load effect, the probability distribution type, distribution parameters and the standard value of load effect in the design reference period of medium-small span simply-supported bridges can be comfirmed. And on basis of the equivalent principle of load effect, a design load value of standard vehicle is recommended in the paper. The theoretical method is provided for the design of the automobile design load of small span bridges under heavy traffic load.