Taking a look at the under-construction Sixth Street Bridge

The first pieces of the viaduct’s swoopy arches will be appearing on the site later this month

By Bianca Barragan Mar 16, 2018, 9:03am PDT

Construction on the Sixth Street Viaduct replacement, a wavy bridge spanning the Los Angeles River that connects Boyle Heights and the Arts District, is picking up speed. With the help of photos from LA-based photographer, Sterling Davis, we took a look at the construction happening on all fronts.

The “falsework”—temporary frames that will support the forthcoming new bridge as it’s built—can now be seen crossing from the Boyle Heights side of the bridge over the 101 Freeway. Additional interim framework is also starting to stretch across the LA River.

The wooden falsework on the freeway side will eventually help form the bottom part of the bridge over the freeway, says John Schroerlucke, chief bridge engineer with Skanska Stacy and Witbeck, the contractor building the new viaduct.

On the Arts District side, towering Y-shaped blue frames stand tall. These forms, called Y-bents, will form the bottom part of the swooping arches that run the length of the new bridge.

Starting at the end of this month, construction crews will begin to fill the forms with concrete.

A March 4 photo of the forms for the soon-to-be-poured Y-bents, which will be the base of the bridge’s swooping arches.

The concrete in each Y-bent will be left to set for about 10 days, at which point the exterior molds for the Y-bents will be removed, exposing some giant concrete Ys to the world.

They won’t be exposed for long. Schroerlucke says not long after the Y-bents are freed from their blue molds, more falsework is built around them so the the undulating arches that will sit atop the Y-bents can be built.

Schroerlucke says the concrete-pouring is expected to continue for about six months, so there’s a good chance passersby can catch a glimpse of the process.

The falsework for the part of the bridge that will cross the LA River is beginning to cross the concrete waterway.

The entire viaduct project is expected to be completed by the end of 2020. (It was originally expected to open in late 2019.) The $482 million dollar project is the largest bridge project in the history of the city. Designed by LA-based architect Michael Maltzan, the viaduct will cross over a new public park.

The old viaduct was demolished in 2016, due to a phenomenon colloquially referred to as “concrete cancer,” which made the structure seismically vulnerable to collapse.