ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.
Issue link: http://www.aspiremagazinebyengineers.com/i/306183
The damage that Hurricane Katrina caused to the I-10 Twin Spans over Lake Pontchartrain created a need for both temporary repairs and a permanent replacement. The size and nature of the project, the schedule, and the project's location, demanded a very efficient solution for the replacement bridge. T h e I - 1 0 Tw i n S p a n s c ro s s L a k e Pontchartrain between Slidell and New Orleans, La. This crossing is approximately 5.5 miles long resulting in a project with a total bridge length of 11 miles. This corridor is important both nationally and locally. It connects the city of New Orleans, New Orleans' ports, and the petro-chemical industry along the Mississippi River. The main navigational channel provides 73 ft of vertical clearance and 200 ft of horizontal clearance and serves both commercial and personal boat traffic. The new bridges provide three lanes in each direction and serve as one of the main evacuation routes for New Orleans. The concerns by the owner and public for expedient construction had to be tempered with the realities of the emergency recovery budget. This $753 million project, entirely funded by the Federal Highway Administration, was constructed by two separate contracting teams. Project budget and schedule had to take into account traffic maintenance, building within the state's rights-of-way, and the limitations of undertaking a construction of this magnitude in a post-Katrina environment. The project is currently over 97% complete and the new bridges should be delivered ahead of schedule. Design goals T h e g o a l s f o r t h e s e re p l a c e m e n t s t r u c t u re s i n c l u d e d b e t t e r s t o r m protection, safe accommodation of six traffic lanes, enhanced barge collision resistance, and utilization of well-known materials and techniques to provide for low maintenance and a long service life. Seven requirements became the blueprint for the project planning. 1. Meet I-10 traffic demands 2. Design a structure that can both resist storm surge and barge impact 3. Provide a 100-year service life 4. Provide for rapid service 5. Minimize environmental impact during construction and operation 6. Avoid interference with existing traffic patterns 7. Work within existing rights-of-way The twin, 5.5-mile-long structures were divided into three parts depending on the structure type. Part 1 consisted of building the horizontal and vertical transitions and ramps with flaring widths. Approximately a ½ mile of structure needed to be designed to resist storm surge. Part 2 consisted of constant width and level-grade spans set above the level of wave force impacts to the profile I-10 TWIN SPAN BRIDGES OVER LAkE PONCHARTRAIN/ BETWEEN NEW ORLEANS AND SLIDELL, LOUISIANA BRIDgE DESIgn EngInEER: Louisiana Department of Transportation and Development (LaDOTD), Baton Rouge, La. COnSTRUCTIOn EngInEERIng AnD InSpECTIOn: Volkert Inc. and LaDOTD, Baton Rouge, La. gEnERAL COnTRACTOR, pARTS 1 AnD 2: Boh Bros. Construction Company LLC, New Orleans, La. gEnERAL COnTRACTOR, pART 3: Traylor, Kiewit, Massman JV, Slidell, La. by Artur W. D'Andrea, Louisiana Department of Transportation and Development Replacement of the I-10 Twin Span Bridges over Lake Pontchartrain Construction of the new Twin Bridges of I-10 that shows the relationship of the new bridges to the original bridges with the New Orleans skyline in the background. 30 | ASPIRE , Spring 2011 Book_Spr11.indb 30 3/30/11 5:09 PM