Highway Axle Load Spectrum Analysis Of Liaoning Province

Extensive WIM data were collected from toll plazas in highway network of Liaoning Province, and filed traffic were video taped for highways of various functional classes and with different numbers of lanes and traffic configurations. A new vehicle classification system was proposed according to the actual situation. The new system can more accurately characterize the traffic loading and composition. It is suggested that the load intervals be 2.5,4.5,9.0 and 13.5 KN for front, single, tandem, and triple axles, respectively, for developing axle load spectra. A new approach was proposed to determine the equivalent axle load factor (EALF). Through the analysis of collected WIM data, the complete axle load spectra parameters of each WIM road were determined, including the axle-load distribution factor, the axle-number factor, the monthly traffic distribution factor, the hour’s traffic distribution factor and the vehicle type distribution factor. In order to compare the differences between AASHTO 1993 pavement design method and Chinese standard design method more intuitively, calculation and analysis were carried out. The paper also determined the distribution of vehicle weight on each toll road, and analyzed the ratio of the overload vehicle. The results showed that there was a serious overload phenomenon on each road, even for non-overload vehicles, there was a large proportion of the bearing axle which owned a higher load than the corresponding standard axle load. These overload axis will cause great damage to the road structure. On the basis of these studies, the paper analyzed the performance of the pavement using AASHTO 2002 mechanics-empirical method.