Keller wins ABC New Orleans 2022 Excellence in Construction award.
Keller was contracted to install support of excavation for launch and receiving shafts to connect a 680-ft micro-tunnel in Avondale, LA. The tunnel would allow carrier pipes to pass under a 14-track railroad switchyard.
Excavating within the influence of the Mississippi River leads to several challenges that must be considered in the geotechnical design, including the presence of soft, organic soils, debris, hydrostatic uplift, and a high groundwater table.
To overcome the challenges, Keller proposed a support of excavation solution for the shafts consisting of internally braced sheet piles with a jet grout bottom seal. “Our jet grout bottom seal design was accepted by the project team,” says Senior Project Manager Chris Rogers.
Construction began the week following Hurricane Ida’s landfall. “We started working amid utility repair in the southern half of Louisiana, but it was imperative we started as quickly as possible,” continues Chris, “Upcoming was the high-water season on the Mississippi River; because of the site’s proximity, we risked delays if worked continued into that season.”
Work progressed well and was on schedule. “Jet grouting within soft soils has also been traditionally challenging,” says Chris, “however, using Keller’s global resources and expertise, a new technique was used that facilitated column installation, providing a bottom seal for the deep excavation.”
Keller completed full shaft construction and excavation with zero safety incidents, meeting all project requirements.