Los Angeles County's $6.3B Metro Purple Line Subway Extension Under Way

Built in three phases, the line will stretch about 9 mi. (14.5 km) and include seven new subway stations.

📅   Fri October 28, 2016 - West Edition #22
Chuck Harvey - CEG CORRESPONDENT


Work is under way on the first section of Los Angeles County’s $6.3 billion Metro Purple Line subway extension.
Work is under way on the first section of Los Angeles County’s $6.3 billion Metro Purple Line subway extension.
Work is under way on the first section of Los Angeles County’s $6.3 billion Metro Purple Line subway extension.
The first section of the extension project includes nearly 4 mi. (6.4 km) of subway westward from the Wilshire-Western Station. Tunnels are about 20 ft. (6 m) in diameter. Crews build two parallel tunnels for train travel in each direction, with a separation of about 20 ft. (6 m).
Besides the tunnels and stations, the project includes train control and signals, communications, traction power supply and distribution, and fare collection systems.
The project begins with excavation of a portion of Wilshire Boulevard and replacing it with concrete deck panels that will allow traffic flow to continue on the street while a station is excavated below.
Crews will pour about 170,000 cu. yds. (129,974 cu m) of structural concrete; 5,500 cu. yds. (4,205 cu m) of concrete pavement; and 25,000 tons (22,680 t) of asphalt.

Work is under way on the first section of Los Angeles County's $6.3 billion Metro Purple Line subway extension that will speed passengers from Los Angeles west to popular destinations like Miracle Mile, Beverly Hills, Century City and Westwood.

Built in three phases, the line will stretch about 9 mi. (14.5 km) and include seven new subway stations.

Metro (Los Angeles County Metropolitan Transportation Authority) is the public transportation operating agency for the County of Los Angeles formed in 1993 due to a merger of the Southern California Rapid Transit District and the Los Angeles County Transportation Commission. The Purple Line is one of Metro's priority projects.

The Metro Board of Directors approved a $2.8 billion contract with Skanska, Traylor and Shea, a Joint Venture to design-build the first phase and section of the project.

Cost for the remainder of the project is estimated at $3.5 billion.

Besides the tunnels and stations, the project includes train control and signals, communications, traction power supply and distribution, and fare collection systems.

The Skanska, Traylor and Shea bid was the highest one for the phase 1 of the project. But Metro staff determined that the three-company venture offered the best opportunity to deliver the project on time and on budget.

Brian Freund is project manager of Skanska, Traylor and Shea, a joint venture.

The extension features more than 50 subcontractors. Some of the major ones include Condon Johnson & Associates of Ontario, Calif. for pile installation; Malcolm Drilling Co. Inc. of Baldwin Park, Calif. for ground improvement and stabilization; Dynalectric of Los Alamitos, Calif., for electrical work; and Group Delta of Irvine, Calif., for geotechnical monitoring.

About 250 workers will be on site during peak production. They include laborers, operators, carpenters, ironworkers and teamsters.

Project Will Connect L.A. to Westside

The extension is considered vital to the area known as Westside for its location just west of Los Angeles.

Overall, the project is a critically-needed subway extension along Wilshire Boulevard, one of the busiest urban corridors in the nation,” said Dave Sotero, communications manager of L.A. Metro. “When it ultimately reaches Westwood-VA, the subway will enable Angelenos to travel between downtown L.A. and Westwood in 25 minutes, a feat that is nearly impossible during the peak rush hour periods.”

It also will connect the two biggest job centers in L.A. County, downtown and Westside.

Sotero said the expansion project is currently on schedule and on budget.

The project has kicked off with construction under Wilshire Boulevard.

The first section of the Purple Line Extension is funded by local Measure R Funds, approved by voters in November 2008 along with federal “New Starts” matching funds and a low-interest loan from the U.S. Department of Transportation's Infrastructure Finance and Innovation Act program.

Metro is already working with the federal government to secure matching funds for the second project section. Metro also is pursuing additional funding to accelerate the entire project through a proposed half-cent sales tax measure that would be on the L.A. County ballot in November.

Concrete & Dirt Removal

Crews will pour about 170,000 cu. yds. (129,974 cu m) of structural concrete; 5,500 cu. yds. (4,205 cu m) of concrete pavement; and 25,000 tons (22,680 t) of asphalt.

Also dirt removal will be done on a large scale and will be disposed of off site. Workers will remove 400,000 cu. yds. (305,822 cu m) of dirt for station excavation and 200,000 cu. yds. (152,911 cu m) of dirt for tunnel excavation.

In addition, crews will remove more than 3,000 cu. yds. (2,294 cu m) of concrete and asphalt, which will be recycled.

First Section

The first section of the extension project includes nearly 4 mi. (6.4 km) of subway westward from the Wilshire-Western Station. New stations along the extended line will include Wilshire-La Brea Station, Wilshire-Fairfax Station and Wilshire-La Cienega Station.

Metro officials expect the first section to be operational in 2023.

Two subsequent sections will add four more stations at downtown Beverly Hills, Century City, Wilshire-Westwood and Wilshire-VA Hospital. Once the subway extension is complete, commuters will travel below ground from downtown Los Angeles to Westwood.

The project begins with excavation of a portion of Wilshire Boulevard and replacing it with concrete deck panels that will allow traffic flow to continue on the street while a station is excavated below.

Heavy Equipment for Section 1

Current heavy equipment on site includes a Liebherr 885 crane; Liebherr 895 crane; 80T Link-Belt crane; Caterpillar 335 excavator; Caterpillar 305 excavator; Caterpillar 938 loader; and a 33K forklift.

Specialty equipment includes two new tunneling machines that are being constructed in Germany and a tower crane for La Brea Station construction.

Each station is about 800 to 1,000 ft. (244 to 105 m) long and 70 ft. (21 m) wide. It contains at least one elevator, two escalators and stairs between the upper and lower levels.

Stations are usually 50 to 60 ft. (15 to 18 m) deep to allow easy passenger circulation from the station platform to the surface.

Preparing a site for station construction usually begins by protecting or relocating any underground utilities like power lines, water lines, sewers, gas pipes, cable-telephone lines and storm drains.

Sections 2 and 3

Section 2 will run 2.6 mi. (4.2 km). Work on Section 2 (phase 2) is scheduled to begin in 2019 and is slated to conclude in 2026.

Section 3 will span 2.9 mi. (4.7 km), with construction is scheduled to start in 2027 and finish in 2035.

Tunnel Construction

Tunnels are about 20 ft. (6 m) in diameter. Crews build two parallel tunnels for train travel in each direction, with a separation of about 20 ft. (6 m).

Tunnels are an average of 50 to 70 ft. (21.3 m) deep, although they can be built deeper between stations. Some portions of the Purple Line Extension will be built at a depth of 130 ft. (39.6 m).

Tunnels between stations will be dug using tunnel boring machines that are lowered into the ground by cranes through a large shaft known as the TBM launch site. The machines tunnel at an average rate of 40 to 50 ft. (12 to 15 m) per day.

Portions of Wilshire Boulevard Closed

On June 10, crews began closing portions of Wilshire Boulevard in the Miracle Mile area in a process that spanned 22 weekends. The Wilshire closures were conducted in three phases: three weekend closures between Detroit Street and La Brea Avenue, three weekend closures at Wilshire and La Brea intersection and 16 weekend closures between La Brea Avenue and Highland Avenue.

Local access for businesses and residents was maintained and sidewalks have been closed intermittently.

“Our construction relations (team) has done an excellent job in helping to mitigate construction impacts with local communities,” Sotero said. He said the team has conducted hundreds of meetings with community members.

Transportation, Economic Benefits of Subway Extension

Los Angeles County is expected to grow by another 750,000 people over the next 10 years. Metro believes it's important to provide more highway and transit alternatives and improvements to keep services in good operating condition.

Based on the analysis conducted during the final environmental impact report, the Purple Line Extension to the Westwood-VA Hospital station will generate about 49,300 daily weekday boardings at the seven new stations.

Also, construction of the Purple Line Extension is projected to generate 52,500 jobs within the region.