Concrete pouring began about 9:30 a.m., and the 260 cubic yards of concrete will be poured at a rate of 4 vertical feet per hour, meaning the process will take between 12 and 14 hours. More than 65 truck loads of concrete are needed per arch, according to the Los Angeles Bureau of Engineering.
“Completing the final arch is a tremendous milestone for the project and for our entire team,” City Engineer Gary Lee Moore said in a statement. “These arches are not only beautiful, but they provide structural support for the viaduct’s deck.”
The $588 million project to replace the previous bridge — which was built in 1932 and deemed seismically deficient — is expected to be completed this summer. The project was funded by the Federal Highway Transportation Administration, Caltrans and the city of Los Angeles.
The viaduct’s “Ribbon of Light” design was created by the architectural firm HNTB Corp. and Los Angeles-based architect Michael Maltzan. The Bureau of Engineering also plans to create a 12-acre park under the bridge to provide access to the L.A. River, public art, recreational programming and more. Last month, the park project received $8.5 million in grants from Prop 68’s Statewide Park Program.
According to the Bureau of Engineering’s plans, the downtown side of the Sixth Street Viaduct park will include a rain garden, planted seating area, a play and performance lawn, a sculpture garden, a meadow, a dog play area, an adult fitness section, cafe and restrooms, a sloped river gateway, an urban forest and terraces.
On the Boyle Heights side, the park’s plans include a skateboard area; a meadow; a picnic area; a synthetic turf soccer field; flexible courts sized for basketball, futsal and volleyball; a play and performance lawn; a children’s play area; a promenade; a landscaped seating area; an adult fitness area; a rain garden; a dog play area and grilling spaces.
The Los Angeles Bureau of Engineering partnered with contractors Skanska-Stacy & Witbeck, which led construction for the viaduct replacement project.