Dynamic Amplification of Traffic Loads on Road Bridges Evaluated Using Probabilistic Traffic Simulations

The traffic loads on road bridges undergo long-term changes as the transport requirements and vehicle technologies develop over time. The current traffic load models of Eurocode were developed decades ago. With the growing database of available axle-load measurements, a reevaluation seems technically possible. However, dynamic amplification factors need to be determined additionally to the quasi-static load effects.
The presented work is based on calculating the effects of simulated traffic flows on a set of chosen bridges. The traffic was generated using probabilistic traffic simulations, which consider different traffic intensities and a combination of probabilistic and deterministic traffic/vehicle parameters. In this work, 20 years of traffic flow was generated and applied on chosen simple bridge models of single-span bridges with spans ranging from 15 to 120 m. Dynamic Amplification Factors were calculated for all significant traffic events.
The results showed that DAF has a decreasing tendency with increasing quasi-static load effects, which was also observed in previous evaluations from monitoring data. Further observed tendencies were decreasing DAF with increasing span length and increasing DAF with decreasing bridge mass per unit length.