Development and validation of a full probabilistic model for traffic load of bridges based on Weigh-In-Motion (WIM) data

It is important to accurately estimate the traffic load effects on bridges for the purpose of design or performance evaluation. Traffic load effects on a bridge forma stochastic process, which requires the development of a site-specific model representing random properties from traffic conditions. However, most design codes and many studies still do not fully consider the site-specific conditions of bridges and rely on conservative assumptions. Therefore, in this study, a full probabilistic traffic load model based on Weigh-In-Motion (WIM) data is developed to consider the site-specific characteristics of vehicles and traffic flow. The statistical model characterizing characteristics of vehicles and traffic floware separately developed. These models describeweight and length of vehicles headway, velocity, and correlation between multiple lanes. Using these statistical models, WIM data are generated by Monte Carlo simulations, and traffic load effects are evaluated by the influence line analysis of the bridges under the generated WIM data. These results are compared with those by actual WIM data to validate the full probabilistic model developed in this study.