THE CONCRETE BRIDGE MAGAZINE

SUMMER 2009

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.

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The 18-mile-long bridge being built on the LA 1 Highway near Leeville, La., will be one of the longest bridges in the Americas when completed. It spans a sensitive wetlands area that has been subjected to coastal erosion and ground subsidence. The new bridge on the LA 1 Highway is being constructed from the top down to minimize impact on the coastal wetlands areas over which the bridge is being constructed. 46 | ASPIRE , Summer 2009 S TAT E T he Louisiana Department of Transportation and Development (LADOTD) has built its bridges predominantly with cast-in-place and precast concrete for decades, especially for short- and medium-span designs. That decision has been driven both by environmental conditions that require high durability and by long-running studies that have made the state a leader in techniques and research involving high-performance concrete (HPC). The state has unique conditions that create challenges, including a large number of waterways and hurricane issues (storm surge, wave forces, and high winds). The state's bread- and-butter design consists of precast, prestressed concrete girders and cast-in-place concrete decks for short- to medium-span length structures. The bridges north of I-10, which account for about 80% of the state's bridge area, are similar to concrete structures designed in other states. However, there are a host of extremely long bridges along and south of I-10. Although the state ranks 21st in total number of bridges, it ranks fourth in total bridge area, indicating the large length of many of its bridges. The region south of I-10 features many navigational c r o s s i n g s a n d a t r e m e n d o u s n u m b e r o f waterways. For this reason, Louisiana has a large number of movable bridges. In all, the annual budget for fixed- and movable-bridge replacements is about $140 million. An example of the extraordinarily long projects that arise is the replacement work underway on an 18-mile-long bridge on the LA 1 highway near Leeville, La. Currently 9 miles are under construction and 9 miles are Research Drives Designs in by Arthur D'Andrea, Paul Fossier, Ray Mumphrey, and Kian Yap, Louisiana Department of Transportation and Development by Arthur D'Andrea, Paul Fossier, Ray Mumphrey, and Kian Yap, Louisiana by Arthur D'Andrea, Paul Fossier, Ray Mumphrey, and Kian Yap, ASPIRE_Summer09.indb 46 6/5/09 2:08:18 PM

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