Time-dependent Reliability Based Permit-checking Of Overloaded Vehicles On Bridges

Based on the axle data provided by Guangxi Province Highway Administration, this paper took the 6-axle trucks part as research data and matched 10000 sets of overloaded vehicle data and a set of permit-checking criterion was established. The main research work and results are:(1) According to the statistic distribution of 6-axle overloaded vehicles axle data, including axle weight and axle base and the double-peak distribution, the axle data was matched by 6 types of statistic models. Then the 6 types statistic distribution models were assessed and compared by introducing Akaike’s Information Criterion, and the optimal data model was selected by comparing and choosing the model which owned the lowest AIC value. The results showed that the axle data fitted by selected optimal model was the closest to the original axle data, and Akaike’s Information Criterion is applicable to the study of axle data.(2) The concepts of “effective axle weight” and “effective axle base” were proposed, which practically describe the situation of axle weight and axle base that actually on the bridge when an overloaded vehicle passing a bridge. After calculating the reliability index of fitted overloaded vehicles, two types of permit-checking method were established according to their axle base, and their time-dependent changes were obtained by study of the time-dependent capability caused by concrete carbonization and steel bar corrosion. Also, the changing situation was obtained and analyzed.(3) The whole process of permit-checking by using proposed criterion was demonstrated, and the results showed that the application of both two proposed method was convenient and time-saving. The results also indicated the relationship of design load level and capacity for overloaded vehicles, as well as the type of overloaded vehicle to which bridge is sensitive, to what the traffic administration department may refer.