It is well known that wind loads result in wind-induced buffeting of slender long-span bridges. Traffic also frequently exists on a slender long-span bridge simultaneously throughout its service life, which can affect the dynamic behavior of the slender structural systems. The nature of the vibration of a slender long-span bridge is further complicated by the dynamic coupling effects among the bridge, wind, and traffic. Fatigue damage is an important consideration in the serviceability performance of slender long-span bridges that typically experience cyclic or repetitive loads, such as those induced by wind and traffic. Stochastic wind and traffic loads, dynamic interaction, and fatigue accumulation for a slender long-span bridge essentially vary over time, with uncertainty contributions from each. Therefore, a reliability-based fatigue assessment model, which can rationally consider the combined load effects from wind and traffic as well as the associated uncertainties, is needed to provide an accurate ...

In recent years, many bridge collapse accidents have been attributed to the passage of extra heavy trucks (EHTs, gross weight $\ge 80\mathrm{t}$ ) in numerous countries. Compared with the standard traffic loads in design specifications, the actual characteristics of EHTs are very difficult to predict because they may be specific to the management, charge policy, or other properties of the route. In a previous publication, the authors researched the characteristics and dynamic impact of EHTs on Chinese expressways. In the current study, long-term traffic monitoring data were statistically analyzed to identify the key characteristics of EHTs on Chinese first-class highways. Based on the EHT scenarios extracted from the weigh-in-motion (WIM) data, which can be used to record the traffic information of moving vehicles, a comprehensive simulation analysis was conducted by an in-house advanced dynamic bridge–traffic interaction model on five typical simply supported T-beam bridges. The bridge response and dynamic impact factors (DIFs) of EHTs were numerically investigated, and reasonable expressions for calculating the DIFs were proposed. Finally, the load effect calibration under EHTs was performed when the road surface condition was average. These findings can be used as additional references for bridge codes and safety assessment by practicing engineers.

In order to improve the shear resistance and structural ductility of the perfobond rib (PBL) connector, a new PBL connector with steel–rubber tenon is proposed in this study, which aims to increase the shear load capacity of the connector while improving the ductility of the connector. First, models of new PBLs are established based on the validated finite element method, and their mechanical properties are compared with other shear connectors. The results show that the stiffness and shear load capacity of the proposed connector can be effectively improved when the steel ring is added, where the shear stiffness can be reduced, and the deformation capacity of the specimen can be improved when the rubber ring is added. When a steel ring with a thickness of 5 mm and a rubber ring with a thickness of 5 mm are involved, the shear load capacity of the connector with steel–rubber tenon is increased by 13.7%, and the shear stiffness is reduced by 37.3% compared to the conventional concrete tenon connector, while the ductility is increased by 75.1% compared to the connector with steel ring tenon. Subsequently, as for the connectors with steel–rubber tenon, the effects of the thickness of the steel ring, the thickness of the rubber ring, the diameter of perforated rebar, the strength of concrete and the strength of perforated steel plate are analyzed based on the finite element model of a PBL. The results show that an increase in the thickness of the steel ring, the diameter of the perforated rebar and the strength of the concrete will cause an increase in the shear stiffness and shear load capacity of the connector; however, an increase in the thickness of the rubber ring can cause a decrease in the shear stiffness and shear load capacity of the connector, while a change in the strength of perforated steel plate has little effect on the shear stiffness and shear load-carrying capacity. Finally, based on the finite element parametric analysis results and the damage mechanism of the proposed connector, a calculation equation applicable to the PBL connector with steel–rubber tenon is presented to predict the shear load capacity of the connector.