Title: Underwater Inspection of the World’s Longest Overall Bridges, Part I
Author(s): Guy F. Lemieux
Publication: Concrete International
Appears on pages(s): 67-70
Keywords: bridge piers; chlorides; corrosion; cracking; inspection;
prestressed concrete; underwater structures;
The twin bridges (constructed in 1955 and 1965) crossing Lake Pontchartrain near New Orleans, La., are supported on more than 9,500 prestressed concrete cylinder piles. This article discusses an ongoing inspection and renovation project, which started in late 1995. A recap of the original construction methods is given. Above and below water inspections began on the north shore of the lake and moved south, first on the older bridge and then on the newer. Cracking found in the pilings was attributed to overdriving. Core samples were taken to study chloride penetration and carbonation. A detailed discussion of an underwater inspection program is provided.