Los Angeles County Metropolitan Transportation Authority (Metro)


Los Angeles, CA


Rail Transportation: Line Segments & Tunnels


Design: Civil Engineering, Structural Engineering, Plumbing, Piping, Fire Protection, Utility Coordination

Purple Line Extension 3 Design-Build Tunnels

The $9.3 billion Los Angeles County Metropolitan Transportation Authority (Metro) Purple Line Extension Project runs 9.3 miles connecting the Koreatown and Westwood neighborhoods via subway. STV is serving as the principal engineer and architect-of-record for the Section 3 tunnels component. The Frontier-Kemper/Tutor Perini joint venture is leading the design-build team.

Section 3 is the last part of this ambitious program and will add 2.56 miles of new heavy rail extension to the Metro system. The section will continue in twin tunnels from the future Century City/Constellation Station site to a new station on the southwest corner of the UCLA campus, under I-405, and then terminating at another new station at the U.S. Department of Veterans Affair property in Westwood.

STV is the lead designer delivering final design of the project that includes guideway tunnels, segmental standard tunnel lining and special seismic fault crossing tunnel lining for twin tunnels, cross passages, and connections to seismically resistant stations. The program also includes a tail track exit shaft for tunnel boring machine launching, utility relocations, ground improvement, ground settlement instrumentation, building protection and other design services during construction.

In addition to performing design services for Section 3 tunnels, STV is also performing design services for the Section 3 stations component and is the principal engineering and lead design firm for the 2.59-mile Section 2 of the Metro Purple Line Extension Project.

Rendering of what the stations may look like, subject to change. Images courtesy of Los Angeles County Metropolitan Transportation Authority (Metro)