6th Street Viaduct Construction

An LA Landmark

The 6th Street Viaduct is one of the most iconic structures in Los Angeles. The nearly 2-mile bridge was completed in 1932 and became an integral part of the city’s culture and landscape, connecting the Arts District and Boyle Heights neighborhoods across the LA River, which provided a vital link between downtown Los Angeles and East Los Angeles. After decades of use, the bridge was deemed structurally deficient and had to be replaced, becoming a major renovation project, with construction beginning in late 2017. The construction of its replacement is one of the largest bridge projects in LA history, and through aerial photography, we have been able to document every stage of its progress from above.

The 6th Street Bridge Project

Officially known as the Sixth Street Viaduct Replacement Project, this $588 million project began in 2016 when workers began demolishing the old bridge. The new bridge features an iconic "Ribbon of Light" arch design, an homage to the historic arch design of the original bridge. It also includes several urban parks, which help create a green space for local residents. With six lanes for cars, four bike lanes, and a pedestrian walkway, it is twice as wide as its predecessor while still maintaining its historical feel.

What’s Included in the Renovation?

The 6th Street Viaduct Renovation project included several structural improvements. The main components were strengthening seismic elements on both sides of the bridge, widening bridge approaches, adding new lighting systems, replacing concrete decking on all spans, and replacing drainage systems throughout the length of the bridge.

Michael Maltzan Architecture was the architecture firm behind the new bridge, using the design by HNTB-Design which won the international design competition for the new Sixth Street Viaduct bridge. Construction was done by Skanska and Stacy and Witbeck, in a joint venture for the Sixth Street Viaduct Replacement Project.

Aerial Photography During Construction

The beauty of this massive undertaking can only truly be appreciated from above. Aerial photographers Mark & Steven have been capturing stunning images since day one, documenting everything from demolition through construction to completion – all with breathtaking clarity. In addition to recording the bridge’s construction progress over time, aerial photography has also enabled us to gain insight into how this impressive structure was built, piece by piece. The construction process has provided many opportunities to capture stunning views of this iconic structure.

How to Build a Bridge

Demolish the existing structure

The first phase of bridge construction involves dismantling the old bridge with heavy machinery. Any obstructions in the way need to be cleared and the site needs to be prepared for building. As with any large project, safety and environmental precautions need to be in place to protect workers and nearby residents during the construction process.

Establish a Solid Foundation

Deep foundations need to be dug into both sides of the river so that the bridge can be securely anchored. Footings are then constructed on both sides of the river that will support the bridge structure in its entirety, ensuring no displacements due to seismic activity or other factors occurring later on during the life of the bridge structure. Concrete is poured into these structural frames to create a strong foundation, with each viaduct piling going 150 feet into the ground.

Supporting the Bridge

Columns and piers are constructed, acting as vertical supports to hold up the bridge superstructure with steel and concrete -- 110,000 tons of concrete and 8,250 tons of steel were used in total. Prefabricated components, including concrete girders, columns, and arches, are constructed offsite to ensure proper installation upstream at the construction site. Once on-site, they are carefully craned into position.

Constructing support infrastructure

Before building the new bridge, crews must lay down a foundation by constructing support structures like pillars and abutments for bridges spanning over land-based parts of the Los Angeles River and preparing deep piling underneath to ensure stability. Concrete substructure Y-Bents are added to reinforce the bridge with large amounts of high-strength steel and concrete used to support each arch span for additional stability against earthquakes.

Build the bridge decking

After laying down the foundation for supports, workers will start constructing decking – installing beams and girders, pouring concrete floorings, attaching permanent steel railings, and connecting sections together.

The New Sixth Street Bridge Opening Weekend

On July 9, 2022, the Sixth Street Bridge finally opened to the public after what seemed like an eternity of construction. To celebrate this grand occasion, various events were planned for opening weekend, ranging from sidewalk vendors to a group of local classic car owners, who brought lowriders for a spirited cruise up and down the bridge. It was an incredible sight as these vintage cars traveled across 6th Street's modern span—talk about old-school charm in a new setting!

A Too Popular Landmark?

The Sixth Street Bridge, built to be an asset to the community, has unfortunately become a source of concern due to illegal activity. Visitors have been using the bridge as a location for dangerous activities such as drag racing and car burnouts. Despite its growing reputation as a destination for such activities, 6th Street Bridge still retains its status as a vital part of the city's infrastructure and remains open for day-to-day use for residents and visitors alike.