RELIABILITY BASED RESEARCH ON TRUCK-LOAD LIMITATION OF MEDIUM-SMALL-SPAN BRIDGES

The standard of truck-load limitation owns an immediate influence on the actual vehicle-load level and on its probability distribution characteristics. Further, the standard may affect the serviceability of constructed infrastructures, for example, bridges. To investigate the truck-load limitation of medium-small-span bridges, a probabilistic method was firstly established. In the second part, the truck-load characteristics were discussed based on long-term WIM (weigh in motion) data and the typical truck types were extracted. Then the higher limits of trucks mass were obtained through the inverse iteration based on the established flexural performance functions and the selected multi-level target-reliability index. The affection of target-reliability index and the 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 conclusions were obtained from the analysis process:the limited truck-weight decreases linearly with the increase of target reliability index, besides this, the influence of differences in regional-load characteristics on the results is non-ignorable. The current standard of overload control is suitable for the load limitation of medium-small-span bridges. Nonetheless, it will be better for different regions to refine the regional-standard base on autologous conditions.