Lessons in Bridge Vulnerability from Hurricane Katrina: Reconnaissance Findings and Analysis of Empirical Data: Fid-Bau Portal

Lessons in Bridge Vulnerability from Hurricane Katrina: Reconnaissance Findings and Analysis of Empirical Data

Padgett, Jamie E. / Arnold, Candase

Hurricane Katrina caused significant damage to the bridges in the Gulf Coast region of the United States, including Louisiana, Mississippi, and Alabama. Damage to these key components of the transportation system can cause significant economic losses and impede post-event recovery and restoration. The overall cost to repair or replace the 44 bridges damaged during Katrina, including emergency repairs, was estimated at well over $1 billion. The paper summarized the findings of reconnaissance along the Gulf Coast by analyzing the observed damage patterns to bridges, including storm surge, wind, and impact damage. These bridges suffered span shifting and unseating, yielded piers, spalling of bent beam, shearing of bearings, and damage to electrical and mechanical equipment, among others. Common features of the severely damaged bridges include low elevation, limited connectivity between superstructure and substructure, and simply supported spans. Potential improved design details and retrofit measures will be presented, drawing upon lessons from Katrina. Nationwide risk assessment packages for lifeline systems lack any reliable input models of bridge fragility to assess the risk to the transportation infrastructure posed by hurricane induced storm surge. As a first step toward the development and validation of quantitative models of bridge reliability under hurricane induced storm surge and wave loading, evidence from the 2005 Hurricane Katrina is used to evaluate hazard intensity measures and bridge characteristics indicative of increasing level of bridge damage. This information can be used for binning of bridges and identification of viable intensity measures for fragility analysis.