Orange County Branch Newsletter

August 2015

Transportation Technical Group

Sixth Street Viaduct Replacement Project Presentation


By Vincent Ip, PE, ASCE OC TTG Board member at large

On July 15, 2015, Mr. Ibrahim Hafeez, project manager and construction manager, City of Los Angeles Bureau of Engineering, gave a very informative presentation about the Sixth Street Viaduct Replacement Project, at UCI’s University Club.  This presentation was hosted by the American Society of Civil Engineers, Orange County Transportation Technical Group, as part of their ongoing series presenting topical projects and programs addressing local and regional transportation needs.

One of the most famous and iconic bridges, the Sixth Street Viaduct acts as a vital connection between the growing Arts District on the west side of the Los Angeles River and the historic neighborhood of Boyle Heights on the east side.  The bridge, built in 1932, spans nearly 4000 feet over the river and two neighborhoods, and has been used to represent Los Angeles' more gritty side in countless movies, music videos and TV commercials, including riverbed car chases.

Due to a rare chemical reaction in the concrete of the structure, known as Alkali Silica Reaction, or ASR, however, the bridge decking and structural supports no longer can resist the bridge’s seismic vulnerability, and the Sixth Street Viaduct will soon be demolished and replaced.

The design of the replacement bridge will accommodate all modes of travel including cars, bicyclists, and pedestrians.  The new bridge will address the need for urban parks, improved mobility, enhance safety, stimulate investment and offer communities a place to gather, recreate and connect.  It is truly a rare transformation opportunity for the City of Los Angeles.

Mr. Ibrahim spoke about project funding, right of way acquisition, environmental requirements, permitting, contracting and schedule issues, as well as touching on some of the design challenges related to the project.  The project will adopt the Construction Manager/General Contractor Project (GM/GC) Delivery Method, which allows the owner and the contractor to negotiate a fair construction cost within the context of a better defined scope and schedule.  As noted by Mr. Ibrahim, a major challenge for the project will be the timeline for right of way acquisition due to the busy work load of the courts.

The first phase of the project is to provide improvements to 11 intersections in the vicinity of the site, with these improvements currently underway.  The next phase is to demolish the existing bridge, scheduled to begin in Fall, 2015.  The approximate two year construction of the replacement bridge will begin in Winter, 2016, followed by landscaping in the Fall of 2018.  The project is scheduled for overall completion in Spring 2019.

With a significant portion of the estimated $420 million project costs being funded by the Federal Highway Transportation Administration and Caltrans, this project represents the largest bridge project in the history of the City.  And with a design that evokes and builds upon the original structure, it is expected that the new Sixth Street Viaduct will take its own place as an iconic Los Angeles structure.

Ted Rigoni, PE, TTG Chair and Ibrahim Hafeez