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  • 21 Aug, 2019

  • By, Wikipedia

Sixth Street Viaduct

The Sixth Street Viaduct, also known as the Sixth Street Bridge, is a viaduct bridge that connects the Arts District in Downtown Los Angeles with the Boyle Heights neighborhood.

The Sixth Street Viaduct spans the Los Angeles River, the Santa Ana Freeway (US 101), and the Golden State Freeway (I-5), as well as Metrolink (Orange County and 91/Perris Valley lines), Amtrak (Pacific Surfliner and Southwest Chief), and Union Pacific (along with Metrolink's Riverside Line) railroad tracks and several local streets. The first incarnation, which opened in 1932 and demolished in 2016, was replaced with the second incarnation in 2022.

The predecessor was composed of three independent structures: the reinforced concrete west segment, the central steel arch segment over the river, and the reinforced concrete east segment. In 1986, the Caltrans bridge survey found the Sixth Street Viaduct eligible for inclusion in the National Register of Historic Places.

The demolition of the predecessor bridge was due to serious structural issues, including several large cracks, resulting from the high alkaline content of the concrete composition, due to architectural unsophistication. As a result, concerns over the structure's seismic instability outweighed its historical status, leading to its closure for demolition and replacement in January 2016. The new replacement bridge was completed six years later and opened on July 9, 2022.

Demolition and replacement

The 1932 incarnation over the Los Angeles River
Walkway and steel arch girder of the original 6th Street Viaduct over the Los Angeles River, 1956
Demolition of the predecessor viaduct bridge in April 2016
The new viaduct during construction as seen from Boyle Heights on June 22, 2021.

During the construction of the viaduct in the 1930s, an onsite plant was used to supply the concrete for construction. However, the quality of the concrete turned out to have a high alkali content and led to an alkali-silica reaction (ASR), which created cracks in the concrete and sapped the strength of the structure. It is the only one of the historic L.A. River viaduct bridges to suffer from ASR.

Estimates stated that the viaduct had a 70% probability of collapse due to a major earthquake within 50 years. After initial demolition plans were delayed, the bridge was closed on January 27, 2016, and demolition began on February 5, 2016. It took nine months to demolish the existing bridge.

Prior to the demolition, Los Angeles mayor Eric Garcetti recorded the R&B song "101SlowJam", backed by musicians from the city's Roosevelt High School, and issued it via a video on his own YouTube channel. The public service announcement video advertised the closure of parts of the 101 Freeway to accommodate the demolition of the viaduct. An estimated 48,000 cubic yards (37,000 m) of concrete, 1,245 tons of structural steel, and 4,200 tons of rebar were hauled away as construction began on the replacement.

The newly completed bridge is designed by architect Michael Maltzan and the HNTB Design-Build team and contractors Skanska and Stacy and Witbeck. The new design has several green spaces built under and around it. Bridge construction has experienced several years-long construction delays and multimillion-dollar cost increases. When opened, the new span included single-direction bicycle lanes separated from motor traffic with rubber curb bumps and impact-forgiving bollards, a design feature that was universally panned as unsafe and dangerous to cyclists using the bridge. A need for emergency vehicle access was given as justification for this design decision by officials, however this has been challenged by advocacy groups and community members. The bridge opened on July 9, 2022.

Building Team :

City of Los Angeles, Bureau of Engineering

Executive Team:

● Ted Allen, P.E. - City Engineer

● Gary Lee Moore, P.E. - Former City Engineer

● Deborah Weintraub, AIA - Chief Deputy City Engineer

● Alfred Mata, P.E. - Deputy City Engineer

● Mary Nemick - Director of Communications

Project Team:

● Julie Allen, P.E. - Program Manager

● Julia Sanchez de la Vega, P.E. - Sr. Civil Engineer

● Shay Doong, P.E. - Sr. Civil Engineer

● Gary Lam, P.E. - Sr. Civil Engineer (PARC Project)

● Karen Keal, P.E., S.E. - Structural Engineer

● Natalie Moore, P.E. - Acting Civil Engineer

● Laura Mojica - Sr. Management Analyst

● Ravil Manapov - Civil Engineer/Field Engineer

● Fausto Miguel Camarena - Civil Engineer/Field Engineer

● Elizabeth Zelaya - Senior Administrative Clerk

Real Estate:

● Uri Jimenez - Chief Real Estate Officer

City of Los Angeles Bureau of Contract Administration:

● John Reamer, Jr. - Inspector of Public Works and General Manager

● Brett McReynolds - Chief Construction Inspector

● Todd Eller - Lead Inspector

City of Los Angeles Department of Transportation:

● Maurice Camacho - Transportation Engineer

City of Los Angeles Bureau of Street Lighting:

● Mary Jane Meer - Division Manager

● Romel Bravo - Street Lighting Engineering Associate

14th Council District:

● Nate Hayward - Capital Projects Director

● Katie Kiefer - DTLA Public Works & Transportation Director

● Susan Lopez - District Director

City Administrative Officer of Los Angeles:

● Bernyce Hollins

● Lisa Johnson-Smith

Office of The Chief Legislative Analyst:

● Matias Farfan

● Matthew Shade

Federal Highway Administration:

● Omar Elkassed - Senior Transportation Engineer

California Department of Transportation:

● Steve Novotny - Chief, District 7 Local Assistance

T.Y. Lin International Group:

● Karen Cormier - Resident Engineer

● Hooshang Alishahi - Structure Representative

HNTB:

● Michael H. Jones, P.E., S.E. - Project Manager, Lead Bridge Engineer ● Semyon Treyger - Complex Bridge Specialist ● Nien Wang - Bridge Engineer ● Rui Lu - Bridge Engineer ● Michael Van Duyn - Bridge Engineer ● Lily Zhang - CADD Lead ● David Graue, AIA - Lead Architect ● John Trautmann, AIA - Architect ● Kourosh Sameni - Lead Drainage Engineer ● Taylor Henderson - Lead Roadway Engineer ● Darold Woodward - Lead Electrical Engineer Michael Maltzan Architecture ● Michael Maltzan, FAIA - Design Principal ● Tim Williams - Managing Principal ● Paul Stoelting - Project Architect

AC Martin:

● Robert L. Newsom, FAIA - Former President, AC Martin (Retired) ● Tom Hsieh, AIA - President, AC Martin Hargreaves/Jones Associates ● Mary Margaret Jones, RLA, FASLA, FAAR - President & CEO ● George Hargreaves, FASLA, FAAR - Design Director ● Gavin McMillan, FASLA - Vice President & Senior Principal ● Megan Esopenko - Senior Associate ● Meghen Quinn, RLA, ASLA, LEED AP - Principal ● Xiaowei Lin - Designer

FAST:

● Hilary Norton - Executive Director

Jacobs:

● Chris Serroels - Project Manager

Psomas:

● Farzad Vakilitabar - Field Engineer

Skanska Stacy and Witbeck (SSW) - Construction Manager / General Contractor:

● Mike Aparicio - Senior Vice President of Operations, Skanska ● Clayton Gilliland - President, Stacy and Witbeck, Inc. ● John Schroerlucke - Chief Bridge Engineer, Skanska Stacy and Witbeck


Cultural depictions of the 1932 incarnation

The former bridge was a well-known local landmark, and was iconic due to appearing in numerous films, television shows, music videos and video games since 1932.

Films

Music videos

Television

Video games

Cultural depictions of the 2022 incarnation

Music videos

Commercials

See also

References

  1. ^ Bernal, Victoria (July 7, 2022). "23 Eye-Opening Photos of the Original Sixth Street Viaduct in Construction". PBS SoCal. Retrieved 10 April 2024.
  2. ^ "History of the Sixth Street Viaduct". Retrieved 24 October 2015.
  3. ^ "Sixth Street Viaduct has Cancer; Suggested Treatment: New Bridge". Southern California Public Radio. Retrieved 24 October 2015.
  4. ^ "Safety Concerns for Sixth Street Bridge". Los Angeles Downtown News. Retrieved 24 October 2015.
  5. ^ "Sixth Street Bridge gets temporary reprieve from demolition". The Eastsider LA. January 11, 2016. Retrieved 12 January 2016.
  6. ^ Pedersen, Erik (January 28, 2016). "[WATCH] 101 Freeway Closure: LA Mayor Eric Garcetti Slow-Jams Reminder". Deadline. Retrieved February 6, 2016.
  7. ^ #101SlowJam on YouTube
  8. ^ "New 6th Street Viaduct is a bridge to a different future". Los Angeles Times. June 1, 2015. Retrieved 24 October 2015.
  9. ^ "Sixth Street Viaduct Replacement Project". NationBuilder. Retrieved 16 January 2017.
  10. ^ "Dramatic new 6th Street Bridge opens, delivering a 'love letter' to Los Angeles". Los Angeles Times. July 9, 2022.
  11. ^ Sharp, Stephen (June 16, 2022). "New Sixth Street Viaduct to open on July 9". Urbanize LA. Urbanize Media.
  12. ^ Koeppel, Dan (February 9, 2016). "Exit L.A.'s Most Cinematic Bridge". The Atlantic.