Sep 15 2015
Arup, a multidisciplinary engineering and consulting firm with a reputation for delivering innovative and sustainable designs, announced today the opening of the No. 7 Line Subway Extension.
Arup worked on the construction of the $2.42bn Metropolitan Transportation Authority (MTA) No. 7 Line Extension, which lengthens the subway line from its current terminus at Times Square to the far west of midtown Manhattan. Through two of the project's key construction contracts, Arup served as tunnel design engineer for the S3 II Tunnel Constructors, (a joint venture of JF Shea, Schiavone, and Skanska), in the construction of the station caverns and as engineer-of-record for the CCA-Halmar International Joint Venture on the ventilation systems.
S3 II engaged Arup for the final design of the initial ground support and the construction sequence design of all drill-and-blast excavations. This phase of the project involved the first large rock cavern to be excavated in Manhattan in 40 years and Arup's work included three 40-50ft diameter rock shafts, a tunnel boring machine (TBM) assembly chamber, a pair of TBM starter and tail tunnels, a TBM reception chamber, five cross passages, two interlocking caverns and the approximately 1000ft long, 60ft tall, 70ft span 34th Street Station cavern. Integral to the success of the project was the knowledge Arup provided in understanding the limitations and opportunities presented by the ground conditions and the proposed excavation methods, as well as the contractual arrangements.
"Arup contributed significantly to the No. 7 Line Extension rock cavern's widely lauded success, resolving many of the rock support and construction sequencing challenges," said Jon Hurt, principal at Arup. "The team is proud to have supported such an important infrastructure project for the city."
As engineer-of-record for the CCA-Halmar International Joint Venture contract at the new 34th Street Station Site L ventilation facility, Arup provided initial ground support design, construction sequence design, construction impact assessment, ventilation design, and field services including the fit-out with mechanical and electrical equipment. This also included implementation of the design of two 40-50ft shafts and a cross passage, as well as two ventilation adits excavated through rock.
In both contract roles, the collaborative approach between Arup and the contractors led to great success during excavation, where teams employed a rapidly buildable and adaptable construction sequence and initial ground support scheme. Both contracts were delivered ahead of schedule and below budget.
"Arup has a long track record of supporting major New York transportation infrastructure projects, including MTA's Second Avenue Subway, the recently opened Fulton Center, Jet Blue Terminal 5 and Delta's new terminal at JFK, and the Tappan Zee Bridge, renamed the New New York Bridge. Arup has numerous experiences working with city, state, and federal prime agencies, as well as construction contractors, in design-build agreements to deliver heavy civil engineering. We have a long and successful track record in design-build delivery of infrastructure both here in New York and around the world," said Craig Covil, principal and infrastructure leader in New York. "The team at Arup is proud to support the continued delivery of major infrastructure projects in New York City."
For more information, please visit The Arup Journal online.