Abstract
The evaluation of existing structures is critical for the efficient management of transportation facilities, especially bridges. According to the Florida Department of Transportation Plan, Safety, and System Management, which include bridge repairs and replacements, a cost of about 30% of all state and federal revenues will be needed in order to get the nation’s bridge integrity to a sufficient level [4]. ASCE estimates $930 billion dollars will be needed within 5 years in order to improve all roads and bridges. This project responds to the growing need to rehabilitate our nation’s bridges by focusing on vehicle-bridge interaction. Frequently, bridges are evaluated using traditional stability methods and simplified static analysis methods.
The main objective of this research was the analysis of an already verified and validated bridge model in order to improve on the dynamic nature of vehicle-bridge interaction. Special attention was made to the improvement of the elastomeric bearing pads in the existing model. The main reason focus was placed on this part of the bridge was due to the fact that these pads are ideal for bridge design because they are economical, effective, and require no maintenance. They deflect in shear to accommodate expansion, contraction, and end rotation of the bridge. There is no need for lubrication, cleaning, nor do they have the opportunity to seize. In order to analyze the improvements of the older bearing pads, an in-lab compression test was created using the same finite element software that was used to create the bridge model. Several compression tests were performed using different material properties in order to determine which set of material characteristics would yield the best results for the improvement of these pads. Once these parameters were determined, they were then verified and validated by a program known as the Roadside Safety Validation and Verification Program, RSVVP. This program is an essential part when developing a model if the model is to be accepted and used to support decision making. The parameters that yield the closest results to the actual field test were then implemented onto the new bridge model. This ensured that the new bridge model was in fact a better representation of what happens in the field. A final calculation of the dynamic load allowance, DLA verified that the vehicle-bridge interaction was successful due to the DLA factor decreasing when compared to the previous calculated DLA factors from an existing vehicle-bridge interaction research.
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