In total, nearly 10 miles (16km) of tunnels will be built in Los Angeles over the next decade for subway projects. That number has the potential to increase by another five miles, if not more.

A contract has been awarded on the Metro Crenshaw project, and notice to proceed is expected on both the Regional Connector Transit Corridor and Purple Line Extensions projects by the end of the summer.

All three of these projects are funded in part by Measure R, a half-cent sales tax approved by 68 per cent of Los Angeles County voters in 2008 that is helping pay for 12 major transit projects. With the local finances secured, the Los Angeles County Metropolitan Transportation Authority (Metro), is qualified to apply for matching funds from the federal government, as well as other state resources.

For example Metro finalised funding in February that will provide a USD 670M federal grant and a USD 160M federally-backed loan for the Regional Connector, effectively clearing the way for construction to begin later this year on the underground project. On top of that, President Obama’s proposed transportation budget for fiscal year 2015 includes USD 100M for the Regional Connector and USD 100M for the Purple Line Extension in New Starts money. If the budget is approved by Congress, that is.

With cash seemingly owing into the city, here’s what’s planned for the underground and the top contenders for building it.

Metro Crenshaw
The Crenshaw/LAX Transit Project is a new 8.5-mile (13.7km) light rail line with eight stations, estimated to cost USD 2.058bn. The alignment has three different underground sections, and is otherwise aerial and at grade.

The scope of work includes 2 miles (3.2km) of cut and cover excavation and U-wall and 1 mile (1.6km) of twin bored tunnels, among other construction including the stations. Jose Ubaldo, communications manager with Metro says, ground conditions are expected to be "both coarse and fine-grained soils consisting of clays, silts, sands, gravels and cobbles typical of the LA basin."

The Walsh-Shea JV will use one TBM for the drives, launching the machine at the future Crenshaw/Exposition station on the southbound excavation first, followed by the northbound. Ubaldo says the TBM is expected to start mining in July 2015.

Contract: Design Build
NTP: September 10, 2013
Groundbreaking: January 21
Operational: 2019

Walsh-Shea Corridor Constructors:

  • Walsh Construction Company
  • J.F. Shea Construction, Inc.
  • HNTB Corporation
  • L. K. Comstock National Transit, Inc.
  • ARUP

Purple line
The Westside Subway Extension of the Metro Purple Line is estimated to cost USD 5.6bn. This project is a 9-mile (14.5km) extension in three sections with seven new stations. Section 1 will extend the line for 3.9 miles (6.3km) and add three stations going west beneath Wilshire Boulevard. Currently in the RFP process, four teams have qualified to bid on the contract for final design and construction. Among the ground conditions in this first section there are tar sands and fossils, and much of the alignment is in the city’s methane zone. Bid documents reference the potential for the contractor to employ a slurry TBM on the project.

This spring, in the area around the La Brea Tar Pits where there are higher levels of tar sands and geotechnical conditions that contain fossils, Metro is constructing an exploratory shaft to better examine ground conditions.

As of April the shaft had reached some 70ft (21.3m) depth and paleontologists had retrieved seeds, bones and smaller marine fossils among other items.

Section 2, which adds 2.6 miles (4.2km) and two stations with construction forecasted to start in 2019. Section 3 adds 2.9 miles (4.9km) and two stations with construction forecasted to start in 2027.

Contract: Design Build
Anticipated Award: June 2014
Anticipated NTP: July 2014
Operational: 2023

The qualified teams are:

  • Impregilo S.p.A., Samsung E & C America, Inc., and Salini USA, Inc. (Westside Transit Partners)
  • Shimmick/Obayashi/FCC
  • Skanska/Traylor/Shea
  • Dragados / Southland / Astaldi (DSA) regional ConneCtor transit Corridor

The Metro Regional Connector Project is a 1.86-mile-long (3km) light rail corridor in downtown Los Angeles with three stations. The line will allow passengers to transfer to four different lines and is forecasted to cost USD 1.366bn. Metro has qualified four teams to bid on the design-build contract. Construction includes 1,350ft (412m) of cut and cover construction, 4,800ft (1,500m) of twin-bore tunnel in two sections, 230ft of SEM tunnel and a wye junction with two portals, according to RFP documents. Metro’s board is expected to select the contract at its April meeting.

Contract: Design Build
Anticipated Award: April 2014
Anticipated NTP: May 2014
Operational: 2020

The qualified teams are:

  • Dragados/Schiavone/Southland
  • Regional Connector Constructors (Skanska USA Civil West California District, Inc., Kiewit Infrastructure West Co.; and Traylor Bros., Inc.)
  • Shea/Walsh/PTG
  • Shimmick/Obayashi/FCC