Using NDT Data for Finite Element Model Calibration and Load Rating of Bridges

The subjectivity inherent in empirical based load rating methods for bridges can be significantly reduced by creating a calibrated finite element model (FEM). The calibration process uses measured structural response from controlled diagnostic load testing to quantify boundary conditions related to support, geometry and stiffness. The resulting calibrated FEM can then be used to predict behavior for other axle configurations as well as multiple lane loadings. This paper will describe the process of collecting strain data from diagnostic load testing and then show how this information is used for calibration of a FEM and calculation of load rating factors.