The Cause of the I-10 Bridge Collapse and the Vulnerability of Coastal Bridges in Hurricane-Prone Areas <p> HR: <span class="hr"> 16:15h<br></span> AN: <span class="an"> OS34A-04 <a href="../absbook/sm05_OS34A.html">[Abstracts]</a><br></span> TI: <span class="ti"> The Cause of the I-10 Bridge Collapse and the Vulnerability of Coastal Bridges in Hurricane-Prone Areas <br></span> AU: <span class="au"> * Chen, Q <br></span> EM: <span class="em"> qchen@jaguar1.usouthal.edu<br></span> AF: <span class="af"> University of South Alabama, Department of Civil Engineering, Mobile, AL 36688-0002 United States <br></span> AU: <span class="au"> Wang, L <br></span> AF: <span class="af"> University of South Alabama, Department of Civil Engineering, Mobile, AL 36688-0002 United States <br></span> AU: <span class="au"> Zhao, H <br></span> AF: <span class="af"> University of South Alabama, Department of Civil Engineering, Mobile, AL 36688-0002 United States <br></span> AU: <span class="au"> Douglass, S L<br></span> AF: <span class="af"> University of South Alabama, Department of Civil Engineering, Mobile, AL 36688-0002 United States <br></span> AB: <span class="ab"> Four hurricanes devastated the Florida and Alabama coasts in 2004. Among them, Hurricane Ivan (2004) caused the collapse of the bridge decks on Interstate Highway 10 (I-10) crossing Escambia Bay in Pensacola, Florida. The goal of the study is to identify and understand the cause of the bridge collapse in order to prevent similar bridge failures in hurricane-prone areas. Two state-of-the-art numerical models have been evaluated, tested and applied to the U.S. Central Gulf Coast for the predictions of storm surges and surface waves on coastal roadways. A methodology of coupling the advanced storm surge model, ADCIRC, with the third-generation spectral wave model, SWAN, have been developed and validated. To reach our specific goal, first, a regional-scale storm surge model for Pensacola Bay is tested against field measurements of surge hydrograph and high watermarks collected by the U.S. Army Corps of Engineers Mobile District. Next, the validated surge model is used to predict the non-stationary water surge and depth-averaged currents in Pensacola Bay generated by Hurricane Ivan. After that, the surge model is coupled with the unsteady wind wave model to predict the storm waves and the elevated mean sea levels (wave setup) along the I-10 Bridge. We then compare the predicted maximum surge heights with the measured high watermarks from the post-Ivan survey and excellent agreement is found. We also correlate the spatial variation of the predicted wave energy flux with the exact locations of the failed bridge decks. The predicted surge and wave conditions along the bridge allow us to estimate the wave slamming and uplifting forces on the bridge decks. The detailed hydrodynamic analysis reveals the cause of and solution to the bridge collapse during Hurricane Ivan. The methodologies we have developed can be utilized to evaluate the vulnerability of coastal bridges in hurricane-prone areas and improve the design of coastal transportation infrastructure. Detailed results will be presented at the conference. The study has been supported by the Federal Highway Administration. <br></span> DE: <span class="de"> 4255 Numerical modeling<br></span> DE: <span class="de"> 4546 Nearshore processes<br></span> DE: <span class="de"> 4556 Sea level variations<br></span> DE: <span class="de"> 4560 Surface waves and tides (1255)<br></span> DE: <span class="de"> 4564 Tsunamis and storm surges<br></span> SC: <span class="sc"> Ocean Sciences [OS]<br></span> MN: <span class="mn"> 2005 Joint Assembly<br></span></p></body></html>