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    Geotechnical

    Project Stories | Interface between new railway tunnel and subway extension tunnel

    About Project

    The New Jersey Transit Authority (NJTA) was planning to build the Trans-Hudson-Express (THE) Tunnel Project. This would create an alternate path into Manhattan along with a secondary underground station for passengers. Simultaneously, the No. 7 Subway Line Extension Project is underway by Metropolitan Transportation Authority Capital Construction (MTACC). This will extend the existing subway line, which currently ends at Times Square Station. The area at which the THE tunnels would run underneath the No. 7 Subway Extension tunnels is referred to as the Interface.

     

    3D view at interface location

    3D view at interface location

     

    Project Name

    Trans Hudson Express Tunnel (THE Tunnel)

    Location

    New York, USA

    Construction Period

    2009 – 2011

    Contractor

    Fay, Spofford & Thorndike (FST)

    Designer

    Gall Zeidler Consultants

     

    Gall Zeidler Consultants (GZ) assisted in assessing the impact of THE tunnel construction on the No. 7 Subway Extension Line tunnels at the Interface. To do so, the host rock and its structural behavior were examined as a result of the envisioned tunneling techniques of both projects. A three-dimensional (3D) numerical analysis was used to support the investigation along with a comprehensive risk analysis.

     

    Interface between Subway Extension and the Tunnel

    Interface between No. 7 Subway Extension and the Tunnel

     

    3D mesh for stability assessment of impact

    3D mesh for stability assessment of impact on existing No. 7 Line tunnels

     

     


     

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