Research on Truck Load Limitation of Medium-Small Span Bridges based on Reliability Theory

The load limitation standard of trucks has an immediate influence on the actual vehicle load level and its probability distribution characteristics. Further, the standard may affect the serviceability of constructed infrastructures, for example bridges. To investigate the truck load limitation issue of small-medium span bridges, a probabilistic model of load limitation analysis was firstly established. In the second part, the truck load characteristics were discussed based on long-term WIM data and the truck types were extracted. Subsequently, the higher limit of truck mass was obtained through inverse iteration based on the established flexural functions and selected multi-level target reliability index. The effect of target reliability index and differences in regional load characteristics on the limited truck mass were discussed based on the analysis results. Further, the applicability of current standard was analyzed through a comparison. The following conclusion were obtained based on the former analysis: the limited truck mass decreases linearly with the increasing of target reliability index. Besides, the influence of differences in regional load characteristics on the results is non-ignorable. The current standard of overload control is suitable for small-medium span bridges. Nonetheless, it is ideal for different regions to refine regional standards based on actual conditions.