Site-Specific Extra-Heavy Truck Load Characteristics and Bridge Safety Assessment

Recently, the occurrence frequency of extra-heavy trucks (EHTs, gross weight ≥80 t) in China has significantly arisen due to the increasing demand of heavy freight transportation. Load characteristics, such as traveling speed, axle weight, and axle distance, of EHTs are different from those of normal traffic loads and vary by region. In the present study, the site-specific load characteristics of EHTs are analyzed based on weigh-in-motion (WIM) data measured from two typical routes of China. Then, the EHT load cases are extracted and a bridge–vehicle simulation is conducted. Finally, the bending capacities of small- to medium-span bridges are assessed. It is found that more attention should be paid to the site-specific load characteristics of EHTs because they are significantly different among different routes. The focused small- to medium-span bridges under EHT load can satisfy the safety requirements and the safety reserves of the bending capacity of such bridges on Chinese highway, which are higher than those of Chinese expressways under EHT load.