The research objective of this project is to study the effect of hurricane induced waves on highway bridge structures in coastal areas. For this, the project we will (1) conduct a series of wave-bridge physical model tests under the assumption of a completely rigid bridge, (2) conduct a second series of wave-bridge physical model tests for a flexible structure, modeling the sway of the bridge using two sets of springs of known stiffness, and (3) conduct a preliminary numerical model investigation to evaluate the performance of an existing fluid-structure model. The research combines expertise in coastal engineering to analyze the wave forcing and structural engineering to analyze the bridge response. Deliverables include developing a fundamental relationship between the wave characteristics (significant wave height and period), geometry (bridge deck, air gap, and water depth), and response (wave loads). A second relationship will be developed to provide probabilities of the extreme wave loads exceeding their certain values for given sea state and problem geometry.
The results of this research will provide new insights into the failure mechanisms of highway bridges subjected to hurricane wave loads, similar to the bridge failures along the US Gulf of Mexico coast during hurricane Ivan in 2004 and Katrina in 2005. The new relationships between wave characteristics and bridge response will provide tools for engineers to evaluate the risk of failure for existing bridges to hurricanes and to design new and retrofit existing bridges to withstand these loads. One graduate student is trained on this project. The research results will be disseminated through journal papers and conference presentations. The project is integrated in an existing K-12 outreach program at the NSF NEES Tsunami Facility at Oregon State University.
