Queens Bored Tunnels and Structures
Services: Temporary Foundations, Support of Excavation, Erection Plans, Precast Stair & Slab Designs, Fall Protection, Work Platform & Formwork Design
Contractors: G.T.F. Joint Venture
Owner: Metropolitan Transportation Authority
Status: In Progress
The Queens Bored Tunnels and Structures contract is part of the MTA’s East Side Access project. The East Side Access project is under construction, and when complete it will connect the Long Island Railroad (LIRR) in Queens to a new terminal beneath Grand Central Terminal in Manhattan. The Queens Bored Tunnels and Structures contract includes boring of four tunnels from the west end to the east end of the LIRR site, construction of emergency exits and a substation building, and construction of associated infrastructure.
Siefert Associates, LLC provided engineered designs, for temporary and permanent construction, tailored to the contractor’s preferred means, methods, and materials. The jointly developed solutions enabled the contractor to complete the work efficiently while minimizing field labor costs. Examples are as follows:
- Complex support of excavation (SOE) work in support of manhole and sewer construction.
- Steel erection plans including prefabrication and trip-up of bracing assemblies in a staging area. Erection of assemblies versus individual components saved significant time and labor costs.
- Design of, and erection plans for, permanent precast concrete stair and floor slab structures. The contractor proposed precast concrete construction as an alternate to the cast in place construction specified in the contract drawings. Off-site fabrication and erection of precast stair and slab pieces, supported by steel shelf angles, proved to be a great benefit to the contractor’s schedule.
- Combined work platform and formwork system for the B13 Substation building. This temporary structure allowed the contractor to successfully complete construction of the floor slab and beam encasements over a challenging sloping grade below.
The Queens Bored Tunnels and Structures contract is on schedule to be completed before the end of 2012.