C+S May 2022 Vol. 8 Issue 5 (web)

L.A. Metro’s Purple Line Extension Project Will Reshape Daily Commute for Los Angeles

When the world’s top athletes descend upon Los Angeles for the 2028 Summer Olympic Games, a new underground rail line will provide a critical means of transportation to many of the venues for athletes and spectators alike. The $9.5 billion Metro Purple Line Extension Project is a nine-mile heavy rail line that will operate as an extension of Los Angeles Metro’s Purple Line from its current terminus at Wilshire/Western Station to a new western terminus in West Los Angeles near the Veterans Adminis - tration (VA) West Los Angeles Medical Center in Westwood. The full project, which is divided into three sections, is on target for completion before Los Angeles hosts the 2028 Olympic Games. The subway extension will connect the D Line (Purple) to several major destinations, with stops near the La Brea Tar Pits and the Los Angeles County Museum of Art, Beverly Hills and the campus of UCLA (where the Olympic Village will be located when Los Angeles hosts the 2028 Summer Olympic Games.) “The nine-mile extension will provide an easy, reliable means of trans- portation to the Westside of Los Angeles, the second-largest job and population center in the entire region,” said Ashok Kothari, WSP USA project director. “This project will improve mobility and reliability, transit service, and access to major activity and employment centers. During the Olympics, it will provide a critical means of transportation for athletes and international spectators.” WSP has been providing environmental and engineering services to the Los Angeles County Metropolitan Transportation Authority (Metro) since early planning studies began in 2007.The firm’s responsibilities have included the preparation of the alternatives analysis, environ- mental impact and funding reports, preliminary engineering, request for proposal (RFP) documents and design support during construction services including systems testing and commissioning. “Activity centers in the study area are served by the city’s infamously congested roadway network, which is forecasted to deteriorate further with increases in population and employment,” Kothari said. The final environmental impact statement and environmental impact report (EIS/EIR), which was prepared by WSP, determined that when the project is completed, travel time from the existing end of the Purple Line, Wilshire/Western Station, to the new Westwood/VA Station will drop from an average of 46 minutes by car to just 15 minutes by subway.

Section 1 Groundbreaking was held in November 2014 for Section 1, a twin- bored, four-mile tunnel extending from the existing Wilshire/West- ern Station and includes underground stations at Wilshire/La Brea, Wilshire/Fairfax and Wilshire/La Cienega. With design work complete and construction having reached the 75 percent mark, Section 1 is on track for opening in 2024. To celebrate the 50 percent completion milestone for Section 1, a “Halfway Completion Ceremony” was held on June 2, 2019 at the La Brea Tar Pits area, attended by local officials, members of the design and construction team, and the local community. It was an appropriate location for the event, as the unique area posed some of the biggest geologic challenges for the extension project. Section 1 Challenges - Construction in the La BreaTar PitsArea Challenges associated with the La Brea tar pit area included the need for careful, accurate assessment of the “tar sand” properties for tunnel and station design, determination of the most appropriate construction methods in the gassy ground and awareness of the potential for en- countering Ice Age-era fossils, similar to those displayed at the La Brea Tar Pits and Museum in the Wilshire/Fairfax Station area. To investigate this area prior to construction, in addition to geotechni- cal borings, WSP designed an exploratory shaft to provide information to designers and contractors on soil properties, construction methods in these conditions, gas monitoring data and construction methods to preserve large fossils should they be encountered. Contractors visited the shaft excavation during the Section 1 early procurement phase. Sections 2 and 3 To stay on target for a fully operational subway extension in 2027, work on the second and third sections of the project is already well under way. A groundbreaking ceremony for Section 2 was held in February 2018.


May 2022 csengineermag.com

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