U.S. Army Corps of Engineers New Orleans, Louisiana, United States
The largest deep soil mixing flood protection project completed in the United States
Quickly building up a major levee to protect New Orleans
Working under fast-track Early Contractor Involvement (ECI) for the U.S. Army Corps of Engineers (USACE), an Alberici joint venture reinforced a 5.3-mile stretch of levee on the outskirts of New Orleans to provide critical protection against 100-year floods. The $350 million project involved raising the average height of the levee by 12 feet and stabilizing 1.8 million cubic yards of soil using a deep soil mixing (DSM) process.
One-of-a-kind deep soil mixing and flood control structures
Using state-of-the-art DSM technology, large augers drilled 63-foot-deep holes in which cement was mixed with soil to create strengthened composite columns. Alberici teamed with specialty foundation contractors, Treviicos of Italy and Fudo of Japan, to complete more than 18,000 of these individual elements, making it the largest DSM flood protection project ever completed in the United States. The project also featured construction of a 2,000-lineal-foot reinforced concrete flood wall and a 250-horsepower pump station.
Collaborating during design to provide major cost savings
Alberici worked closely with USACE and their engineering consultants during the design phase to perform extensive constructability and value analysis, including soil validation, bench testing, and foundation analysis. During this phase, Alberici devised a plan to use recycled DSM spoils instead of off-site fill material to increase the height of the levee cross sections. In total, the team was able to reuse 350,000 cubic yards of DSM spoils, resulting in nearly $62 million in cost savings under the initial target price.
Accelerating schedule to meet critical flood protection deadlines
To meet the project’s aggressive schedule, Alberici continuously worked two shifts, placing up to 30,000 cubic yards of material each day. To keep materials steadily flowing to the project, Alberici installed a 30-foot wide, six-mile road and a temporary floating bridge. Ultimately, the project was completed on schedule.
Taking care of the environment
All work was completed while maintaining the integrity of the environmentally sensitive Bayou Sauvage National Wildlife Refuge, which immediately bordered the project on the inboard side of the levee. Alberici implemented preventative measures to ensure protected land and wildlife were not harmed during construction.