Sixth Street Viaduct Replacement Project
The City of Los Angeles' Sixth Street Viaduct Replacement Project is the replacement of the original bridge structure with a new viaduct that will provide exceptional pedestrian and bicycle access, safer traffic and goods movement, and 12 acres of open and recreational space, including an arts plaza and public art. The Bureau of Engineering, led by City Engineer Gary Lee Moore, is leading the project, along with engineering firm HNTB and architectural firm Michael Maltzan Architecture, selected through an international design competition. The project contractor is Skanska-Stacy and Witbeck (SSW). The new viaduct will be completed in Summer of 2022. The total project cost is $588 million.
- The length of the viaduct from Mateo Street to just east of the 101 Freeway is approximately 3,500 feet.
- The viaduct will span 18 railroad tracks operated by 5 different railroad agencies.
- The width of the deck of the viaduct will be 100', an increase of 40 feet.
- The new viaduct has 23 columns and 2 abutments.
- The piles extend an average of 150' underground, which is the equivalent to a 15-story building.
- Cables have a diameter of 2 3/4 inches.
- 110,000 tons of concrete and 8,250 tons of steel will be needed to build the new viaduct.
- Sidewalks on each side of the viaduct will vary from 8' to 14'.
- 10' wide bike lanes will run along each side of the viaduct.
- Two bicycle/pedestrian ramp structures will provide access to ground level on each side of the river.
- The east ramp will be a 3.5 level helical structure connected by paths to both north and south sides of the viaduct.
- The helix will be 790' long, 12' wide, and 45' tall. The ramp from the south side of the structure is 640' long.
- There will be a 510' long west ramp from the north side of the deck to the ground near Mateo Ave.
- There will be five stairs connecting the ground and the viaduct sidewalk, with climbing heights ranging between 25' and 60'.
- There are 10 sets of arches.
- Arches have a 9 degree cant and support the bridge deck with a cable network.
- The arches are 10' wide, with a typical arch span of 300'.
- There are three different arch heights on the new viaduct:
- Over the railroads: 60' - 2 pairs
- Over US 101: 40' - 1 pair
- Over LA River: 30' - 1 pair
- Remaining arches: 30' - 6 pairs
Seismic Base Isolation
- The columns and abutments use triple friction pendulum bearings for seismic base isolation, which will allow movement of 30" in any lateral direction.
Sixth Street PARC
- There will be 12-acres of open and recreational space under the viaduct, including access to the LA River, an arts plaza, public art and numerous community amenities.