Bridge Management, Inspection and Sustainability
Full Session with Abstracts
340652-1 - Benefits and Challenges of Automating Refined Load Ratings for Girder Bridges
Friday, April 20
11:00 AM - 12:30 PM
Current industry trends in bridge load ratings acknowledge both the benefits of refined ratings and the added expense. Refined ratings are used sparingly in part because of the added level of resources needed produce and evaluate analytical models. This additional effort consists of critical broad engineering decisions such as modeling approach and a substantial amount of tedious and error prone tasks of manipulating a finite element analysis (FEA) program via a Graphical User Interface (GUI) to build and analyze a model. By separating the broad engineering decisions and passing them as input into a series of automated algorithms that carry out model building, analysis and results extraction, the refined rating process can be made much more efficient and consistent. The biggest challenge of automating this process is balancing the flexibility and robustness of the process with the amount of engineering overhead required to develop the necessary input. An automated refined load rating needs to accommodate bridge configurations that fall outside the bounds of applicability of distribution factors used in approximate methods. As an example, these distribution factors aren’t applicable to bridges with features such as variable skews or curvature, which present additional challenges in model generation as well. Once established, an automated process enables a load rating engineer to spend their time studying structural behavior and the effect of modeling decisions or rehabilitation strategies rather than manipulating a GUI. Automation also makes a process completely repeatable and more transparent than traditional refined analysis. This paper discusses the refined rating process, as well as the challenges and benefits of automating this process for multi-girder bridges.